thodg/got/lib/worktree.c

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• Hash : 9fdde394
  Author :
  Date : 2022-06-04T14:13:46
  

  got stage: implicitly unstage when staging the reverse of the staged diff otherwise we end up with a staged empty edit for that file. ok stsp@

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• lib/worktree.c

• /*
   * Copyright (c) 2018, 2019, 2020 Stefan Sperling <stsp@openbsd.org>
   *
   * Permission to use, copy, modify, and distribute this software for any
   * purpose with or without fee is hereby granted, provided that the above
   * copyright notice and this permission notice appear in all copies.
   *
   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
   */
  
  #include <sys/stat.h>
  #include <sys/queue.h>
  #include <sys/tree.h>
  
  #include <dirent.h>
  #include <limits.h>
  #include <stddef.h>
  #include <string.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <time.h>
  #include <fcntl.h>
  #include <errno.h>
  #include <unistd.h>
  #include <sha1.h>
  #include <zlib.h>
  #include <fnmatch.h>
  #include <libgen.h>
  #include <uuid.h>
  #include <util.h>
  
  #include "got_error.h"
  #include "got_repository.h"
  #include "got_reference.h"
  #include "got_object.h"
  #include "got_path.h"
  #include "got_cancel.h"
  #include "got_worktree.h"
  #include "got_opentemp.h"
  #include "got_diff.h"
  
  #include "got_lib_worktree.h"
  #include "got_lib_sha1.h"
  #include "got_lib_fileindex.h"
  #include "got_lib_inflate.h"
  #include "got_lib_delta.h"
  #include "got_lib_object.h"
  #include "got_lib_object_parse.h"
  #include "got_lib_object_create.h"
  #include "got_lib_object_idset.h"
  #include "got_lib_diff.h"
  #include "got_lib_gotconfig.h"
  
  #ifndef MIN
  #define	MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
  #endif
  
  #define GOT_MERGE_LABEL_MERGED	"merged change"
  #define GOT_MERGE_LABEL_BASE	"3-way merge base"
  
  static const struct got_error *
  create_meta_file(const char *path_got, const char *name, const char *content)
  {
  	const struct got_error *err = NULL;
  	char *path;
  
  	if (asprintf(&path, "%s/%s", path_got, name) == -1)
  		return got_error_from_errno("asprintf");
  
  	err = got_path_create_file(path, content);
  	free(path);
  	return err;
  }
  
  static const struct got_error *
  update_meta_file(const char *path_got, const char *name, const char *content)
  {
  	const struct got_error *err = NULL;
  	FILE *tmpfile = NULL;
  	char *tmppath = NULL;
  	char *path = NULL;
  
  	if (asprintf(&path, "%s/%s", path_got, name) == -1) {
  		err = got_error_from_errno("asprintf");
  		path = NULL;
  		goto done;
  	}
  
  	err = got_opentemp_named(&tmppath, &tmpfile, path);
  	if (err)
  		goto done;
  
  	if (content) {
  		int len = fprintf(tmpfile, "%s\n", content);
  		if (len != strlen(content) + 1) {
  			err = got_error_from_errno2("fprintf", tmppath);
  			goto done;
  		}
  	}
  
  	if (rename(tmppath, path) != 0) {
  		err = got_error_from_errno3("rename", tmppath, path);
  		unlink(tmppath);
  		goto done;
  	}
  
  done:
  	if (fclose(tmpfile) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", tmppath);
  	free(tmppath);
  	return err;
  }
  
  static const struct got_error *
  write_head_ref(const char *path_got, struct got_reference *head_ref)
  {
  	const struct got_error *err = NULL;
  	char *refstr = NULL;
  
  	if (got_ref_is_symbolic(head_ref)) {
  		refstr = got_ref_to_str(head_ref);
  		if (refstr == NULL)
  			return got_error_from_errno("got_ref_to_str");
  	} else {
  		refstr = strdup(got_ref_get_name(head_ref));
  		if (refstr == NULL)
  			return got_error_from_errno("strdup");
  	}
  	err = update_meta_file(path_got, GOT_WORKTREE_HEAD_REF, refstr);
  	free(refstr);
  	return err;
  }
  
  const struct got_error *
  got_worktree_init(const char *path, struct got_reference *head_ref,
      const char *prefix, struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	struct got_object_id *commit_id = NULL;
  	uuid_t uuid;
  	uint32_t uuid_status;
  	int obj_type;
  	char *path_got = NULL;
  	char *formatstr = NULL;
  	char *absprefix = NULL;
  	char *basestr = NULL;
  	char *uuidstr = NULL;
  
  	if (strcmp(path, got_repo_get_path(repo)) == 0) {
  		err = got_error(GOT_ERR_WORKTREE_REPO);
  		goto done;
  	}
  
  	err = got_ref_resolve(&commit_id, repo, head_ref);
  	if (err)
  		return err;
  	err = got_object_get_type(&obj_type, repo, commit_id);
  	if (err)
  		return err;
  	if (obj_type != GOT_OBJ_TYPE_COMMIT)
  		return got_error(GOT_ERR_OBJ_TYPE);
  
  	if (!got_path_is_absolute(prefix)) {
  		if (asprintf(&absprefix, "/%s", prefix) == -1)
  			return got_error_from_errno("asprintf");
  	}
  
  	/* Create top-level directory (may already exist). */
  	if (mkdir(path, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
  		err = got_error_from_errno2("mkdir", path);
  		goto done;
  	}
  
  	/* Create .got directory (may already exist). */
  	if (asprintf(&path_got, "%s/%s", path, GOT_WORKTREE_GOT_DIR) == -1) {
  		err = got_error_from_errno("asprintf");
  		goto done;
  	}
  	if (mkdir(path_got, GOT_DEFAULT_DIR_MODE) == -1 && errno != EEXIST) {
  		err = got_error_from_errno2("mkdir", path_got);
  		goto done;
  	}
  
  	/* Create an empty lock file. */
  	err = create_meta_file(path_got, GOT_WORKTREE_LOCK, NULL);
  	if (err)
  		goto done;
  
  	/* Create an empty file index. */
  	err = create_meta_file(path_got, GOT_WORKTREE_FILE_INDEX, NULL);
  	if (err)
  		goto done;
  
  	/* Write the HEAD reference. */
  	err = write_head_ref(path_got, head_ref);
  	if (err)
  		goto done;
  
  	/* Record our base commit. */
  	err = got_object_id_str(&basestr, commit_id);
  	if (err)
  		goto done;
  	err = create_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, basestr);
  	if (err)
  		goto done;
  
  	/* Store path to repository. */
  	err = create_meta_file(path_got, GOT_WORKTREE_REPOSITORY,
  	    got_repo_get_path(repo));
  	if (err)
  		goto done;
  
  	/* Store in-repository path prefix. */
  	err = create_meta_file(path_got, GOT_WORKTREE_PATH_PREFIX,
  	    absprefix ? absprefix : prefix);
  	if (err)
  		goto done;
  
  	/* Generate UUID. */
  	uuid_create(&uuid, &uuid_status);
  	if (uuid_status != uuid_s_ok) {
  		err = got_error_uuid(uuid_status, "uuid_create");
  		goto done;
  	}
  	uuid_to_string(&uuid, &uuidstr, &uuid_status);
  	if (uuid_status != uuid_s_ok) {
  		err = got_error_uuid(uuid_status, "uuid_to_string");
  		goto done;
  	}
  	err = create_meta_file(path_got, GOT_WORKTREE_UUID, uuidstr);
  	if (err)
  		goto done;
  
  	/* Stamp work tree with format file. */
  	if (asprintf(&formatstr, "%d", GOT_WORKTREE_FORMAT_VERSION) == -1) {
  		err = got_error_from_errno("asprintf");
  		goto done;
  	}
  	err = create_meta_file(path_got, GOT_WORKTREE_FORMAT, formatstr);
  	if (err)
  		goto done;
  
  done:
  	free(commit_id);
  	free(path_got);
  	free(formatstr);
  	free(absprefix);
  	free(basestr);
  	free(uuidstr);
  	return err;
  }
  
  const struct got_error *
  got_worktree_match_path_prefix(int *match, struct got_worktree *worktree,
      const char *path_prefix)
  {
  	char *absprefix = NULL;
  
  	if (!got_path_is_absolute(path_prefix)) {
  		if (asprintf(&absprefix, "/%s", path_prefix) == -1)
  			return got_error_from_errno("asprintf");
  	}
  	*match = (strcmp(absprefix ? absprefix : path_prefix,
  	    worktree->path_prefix) == 0);
  	free(absprefix);
  	return NULL;
  }
  
  const char *
  got_worktree_get_head_ref_name(struct got_worktree *worktree)
  {
  	return worktree->head_ref_name;
  }
  
  const struct got_error *
  got_worktree_set_head_ref(struct got_worktree *worktree,
      struct got_reference *head_ref)
  {
  	const struct got_error *err = NULL;
  	char *path_got = NULL, *head_ref_name = NULL;
  
  	if (asprintf(&path_got, "%s/%s", worktree->root_path,
  	    GOT_WORKTREE_GOT_DIR) == -1) {
  		err = got_error_from_errno("asprintf");
  		path_got = NULL;
  		goto done;
  	}
  
  	head_ref_name = strdup(got_ref_get_name(head_ref));
  	if (head_ref_name == NULL) {
  		err = got_error_from_errno("strdup");
  		goto done;
  	}
  
  	err = write_head_ref(path_got, head_ref);
  	if (err)
  		goto done;
  
  	free(worktree->head_ref_name);
  	worktree->head_ref_name = head_ref_name;
  done:
  	free(path_got);
  	if (err)
  		free(head_ref_name);
  	return err;
  }
  
  struct got_object_id *
  got_worktree_get_base_commit_id(struct got_worktree *worktree)
  {
  	return worktree->base_commit_id;
  }
  
  const struct got_error *
  got_worktree_set_base_commit_id(struct got_worktree *worktree,
      struct got_repository *repo, struct got_object_id *commit_id)
  {
  	const struct got_error *err;
  	struct got_object *obj = NULL;
  	char *id_str = NULL;
  	char *path_got = NULL;
  
  	if (asprintf(&path_got, "%s/%s", worktree->root_path,
  	    GOT_WORKTREE_GOT_DIR) == -1) {
  		err = got_error_from_errno("asprintf");
  		path_got = NULL;
  		goto done;
  	}
  
  	err = got_object_open(&obj, repo, commit_id);
  	if (err)
  		return err;
  
  	if (obj->type != GOT_OBJ_TYPE_COMMIT) {
  		err = got_error(GOT_ERR_OBJ_TYPE);
  		goto done;
  	}
  
  	/* Record our base commit. */
  	err = got_object_id_str(&id_str, commit_id);
  	if (err)
  		goto done;
  	err = update_meta_file(path_got, GOT_WORKTREE_BASE_COMMIT, id_str);
  	if (err)
  		goto done;
  
  	free(worktree->base_commit_id);
  	worktree->base_commit_id = got_object_id_dup(commit_id);
  	if (worktree->base_commit_id == NULL) {
  		err = got_error_from_errno("got_object_id_dup");
  		goto done;
  	}
  done:
  	if (obj)
  		got_object_close(obj);
  	free(id_str);
  	free(path_got);
  	return err;
  }
  
  const struct got_gotconfig *
  got_worktree_get_gotconfig(struct got_worktree *worktree)
  {
  	return worktree->gotconfig;
  }
  
  static const struct got_error *
  lock_worktree(struct got_worktree *worktree, int operation)
  {
  	if (flock(worktree->lockfd, operation | LOCK_NB) == -1)
  		return (errno == EWOULDBLOCK ? got_error(GOT_ERR_WORKTREE_BUSY)
  		    : got_error_from_errno2("flock",
  		    got_worktree_get_root_path(worktree)));
  	return NULL;
  }
  
  static const struct got_error *
  add_dir_on_disk(struct got_worktree *worktree, const char *path)
  {
  	const struct got_error *err = NULL;
  	char *abspath;
  
  	if (asprintf(&abspath, "%s/%s", worktree->root_path, path) == -1)
  		return got_error_from_errno("asprintf");
  
  	err = got_path_mkdir(abspath);
  	if (err && err->code == GOT_ERR_ERRNO && errno == EEXIST) {
  		struct stat sb;
  		err = NULL;
  		if (lstat(abspath, &sb) == -1) {
  			err = got_error_from_errno2("lstat", abspath);
  		} else if (!S_ISDIR(sb.st_mode)) {
  			/* TODO directory is obstructed; do something */
  			err = got_error_path(abspath, GOT_ERR_FILE_OBSTRUCTED);
  		}
  	}
  	free(abspath);
  	return err;
  }
  
  static const struct got_error *
  check_file_contents_equal(int *same, FILE *f1, FILE *f2)
  {
  	const struct got_error *err = NULL;
  	uint8_t fbuf1[8192];
  	uint8_t fbuf2[8192];
  	size_t flen1 = 0, flen2 = 0;
  
  	*same = 1;
  
  	for (;;) {
  		flen1 = fread(fbuf1, 1, sizeof(fbuf1), f1);
  		if (flen1 == 0 && ferror(f1)) {
  			err = got_error_from_errno("fread");
  			break;
  		}
  		flen2 = fread(fbuf2, 1, sizeof(fbuf2), f2);
  		if (flen2 == 0 && ferror(f2)) {
  			err = got_error_from_errno("fread");
  			break;
  		}
  		if (flen1 == 0) {
  			if (flen2 != 0)
  				*same = 0;
  			break;
  		} else if (flen2 == 0) {
  			if (flen1 != 0)
  				*same = 0;
  			break;
  		} else if (flen1 == flen2) {
  			if (memcmp(fbuf1, fbuf2, flen2) != 0) {
  				*same = 0;
  				break;
  			}
  		} else {
  			*same = 0;
  			break;
  		}
  	}
  
  	return err;
  }
  
  static const struct got_error *
  check_files_equal(int *same, FILE *f1, FILE *f2)
  {
  	struct stat sb;
  	size_t size1, size2;
  
  	*same = 1;
  
  	if (fstat(fileno(f1), &sb) != 0)
  		return got_error_from_errno("fstat");
  	size1 = sb.st_size;
  
  	if (fstat(fileno(f2), &sb) != 0)
  		return got_error_from_errno("fstat");
  	size2 = sb.st_size;
  
  	if (size1 != size2) {
  		*same = 0;
  		return NULL;
  	}
  
  	if (fseek(f1, 0L, SEEK_SET) == -1)
  		return got_ferror(f1, GOT_ERR_IO);
  	if (fseek(f2, 0L, SEEK_SET) == -1)
  		return got_ferror(f2, GOT_ERR_IO);
  
  	return check_file_contents_equal(same, f1, f2);
  }
  
  static const struct got_error *
  copy_file_to_fd(off_t *outsize, FILE *f, int outfd)
  {
  	uint8_t fbuf[65536];
  	size_t flen;
  	ssize_t outlen;
  
  	*outsize = 0;
  
  	if (fseek(f, 0L, SEEK_SET) == -1)
  		return got_ferror(f, GOT_ERR_IO);
  
  	for (;;) {
  		flen = fread(fbuf, 1, sizeof(fbuf), f);
  		if (flen == 0) {
  			if (ferror(f))
  				return got_error_from_errno("fread");
  			if (feof(f))
  				break;
  		}
  		outlen = write(outfd, fbuf, flen);
  		if (outlen == -1)
  			return got_error_from_errno("write");
  		if (outlen != flen)
  			return got_error(GOT_ERR_IO);
  		*outsize += outlen;
  	}
  
  	return NULL;
  }
  
  static const struct got_error *
  merge_binary_file(int *overlapcnt, int merged_fd,
      FILE *f_deriv, FILE *f_orig, FILE *f_deriv2,
      const char *label_deriv, const char *label_orig, const char *label_deriv2,
      const char *ondisk_path)
  {
  	const struct got_error *err = NULL;
  	int same_content, changed_deriv, changed_deriv2;
  	int fd_orig = -1, fd_deriv = -1, fd_deriv2 = -1;
  	off_t size_orig = 0, size_deriv = 0, size_deriv2 = 0;
  	char *path_orig = NULL, *path_deriv = NULL, *path_deriv2 = NULL;
  	char *base_path_orig = NULL, *base_path_deriv = NULL;
  	char *base_path_deriv2 = NULL;
  
  	*overlapcnt = 0;
  
  	err = check_files_equal(&same_content, f_deriv, f_deriv2);
  	if (err)
  		return err;
  
  	if (same_content)
  		return copy_file_to_fd(&size_deriv, f_deriv, merged_fd);
  
  	err = check_files_equal(&same_content, f_deriv, f_orig);
  	if (err)
  		return err;
  	changed_deriv = !same_content;
  	err = check_files_equal(&same_content, f_deriv2, f_orig);
  	if (err)
  		return err;
  	changed_deriv2 = !same_content;
  
  	if (changed_deriv && changed_deriv2) {
  		*overlapcnt = 1;
  		if (asprintf(&base_path_orig, "%s-orig", ondisk_path) == -1) {
  			err = got_error_from_errno("asprintf");
  			goto done;
  		}
  		if (asprintf(&base_path_deriv, "%s-1", ondisk_path) == -1) {
  			err = got_error_from_errno("asprintf");
  			goto done;
  		}
  		if (asprintf(&base_path_deriv2, "%s-2", ondisk_path) == -1) {
  			err = got_error_from_errno("asprintf");
  			goto done;
  		}
  		err = got_opentemp_named_fd(&path_orig, &fd_orig,
  		    base_path_orig);
  		if (err)
  			goto done;
  		err = got_opentemp_named_fd(&path_deriv, &fd_deriv,
  		    base_path_deriv);
  		if (err)
  			goto done;
  		err = got_opentemp_named_fd(&path_deriv2, &fd_deriv2,
  		    base_path_deriv2);
  		if (err)
  			goto done;
  		err = copy_file_to_fd(&size_orig, f_orig, fd_orig);
  		if (err)
  			goto done;
  		err = copy_file_to_fd(&size_deriv, f_deriv, fd_deriv);
  		if (err)
  			goto done;
  		err = copy_file_to_fd(&size_deriv2, f_deriv2, fd_deriv2);
  		if (err)
  			goto done;
  		if (dprintf(merged_fd, "Binary files differ and cannot be "
  		    "merged automatically:\n") < 0) {
  			err = got_error_from_errno("dprintf");
  			goto done;
  		}
  		if (dprintf(merged_fd, "%s%s%s\nfile %s\n",
  		    GOT_DIFF_CONFLICT_MARKER_BEGIN,
  		    label_deriv ? " " : "",
  		    label_deriv ? label_deriv : "",
  		    path_deriv) < 0) {
  			err = got_error_from_errno("dprintf");
  			goto done;
  		}
  		if (size_orig > 0) {
  			if (dprintf(merged_fd, "%s%s%s\nfile %s\n",
  			    GOT_DIFF_CONFLICT_MARKER_ORIG,
  			    label_orig ? " " : "",
  			    label_orig ? label_orig : "",
  			    path_orig) < 0) {
  				err = got_error_from_errno("dprintf");
  				goto done;
  			}
  		}
  		if (dprintf(merged_fd, "%s\nfile %s\n%s%s%s\n",
  		    GOT_DIFF_CONFLICT_MARKER_SEP,
  		    path_deriv2,
  		    GOT_DIFF_CONFLICT_MARKER_END,
  		    label_deriv2 ?  " " : "",
  		    label_deriv2 ? label_deriv2 : "") < 0) {
  			err = got_error_from_errno("dprintf");
  			goto done;
  		}
  	} else if (changed_deriv)
  		err = copy_file_to_fd(&size_deriv, f_deriv, merged_fd);
  	else if (changed_deriv2)
  		err = copy_file_to_fd(&size_deriv2, f_deriv2, merged_fd);
  done:
  	if (size_orig == 0 && path_orig && unlink(path_orig) == -1 &&
  	    err == NULL)
  		err = got_error_from_errno2("unlink", path_orig);
  	if (fd_orig != -1 && close(fd_orig) == -1 && err == NULL)
  		err = got_error_from_errno2("close", path_orig);
  	if (fd_deriv != -1 && close(fd_deriv) == -1 && err == NULL)
  		err = got_error_from_errno2("close", path_deriv);
  	if (fd_deriv2 != -1 && close(fd_deriv2) == -1 && err == NULL)
  		err = got_error_from_errno2("close", path_deriv2);
  	free(path_orig);
  	free(path_deriv);
  	free(path_deriv2);
  	free(base_path_orig);
  	free(base_path_deriv);
  	free(base_path_deriv2);
  	return err;
  }
  
  /*
   * Perform a 3-way merge where the file f_orig acts as the common
   * ancestor, the file f_deriv acts as the first derived version,
   * and the file f_deriv2 acts as the second derived version.
   * The merge result will be written to a new file at ondisk_path; any
   * existing file at this path will be replaced.
   */
  static const struct got_error *
  merge_file(int *local_changes_subsumed, struct got_worktree *worktree,
      FILE *f_orig, FILE *f_deriv, FILE *f_deriv2, const char *ondisk_path,
      const char *path, uint16_t st_mode,
      const char *label_orig, const char *label_deriv, const char *label_deriv2,
      enum got_diff_algorithm diff_algo, struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	const struct got_error *err = NULL;
  	int merged_fd = -1;
  	FILE *f_merged = NULL;
  	char *merged_path = NULL, *base_path = NULL;
  	int overlapcnt = 0;
  	char *parent = NULL;
  
  	*local_changes_subsumed = 0;
  
  	err = got_path_dirname(&parent, ondisk_path);
  	if (err)
  		return err;
  
  	if (asprintf(&base_path, "%s/got-merged", parent) == -1) {
  		err = got_error_from_errno("asprintf");
  		goto done;
  	}
  
  	err = got_opentemp_named_fd(&merged_path, &merged_fd, base_path);
  	if (err)
  		goto done;
  
  	err = got_merge_diff3(&overlapcnt, merged_fd, f_deriv, f_orig,
  	    f_deriv2, label_deriv, label_orig, label_deriv2, diff_algo);
  	if (err) {
  		if (err->code != GOT_ERR_FILE_BINARY)
  			goto done;
  		err = merge_binary_file(&overlapcnt, merged_fd, f_deriv,
  		    f_orig, f_deriv2, label_deriv, label_orig, label_deriv2,
  		    ondisk_path);
  		if (err)
  			goto done;
  	}
  
  	err = (*progress_cb)(progress_arg,
  	    overlapcnt > 0 ? GOT_STATUS_CONFLICT : GOT_STATUS_MERGE, path);
  	if (err)
  		goto done;
  
  	if (fsync(merged_fd) != 0) {
  		err = got_error_from_errno("fsync");
  		goto done;
  	}
  
  	f_merged = fdopen(merged_fd, "r");
  	if (f_merged == NULL) {
  		err = got_error_from_errno("fdopen");
  		goto done;
  	}
  	merged_fd = -1;
  
  	/* Check if a clean merge has subsumed all local changes. */
  	if (overlapcnt == 0) {
  		err = check_files_equal(local_changes_subsumed, f_deriv,
  		    f_merged);
  		if (err)
  			goto done;
  	}
  
  	if (fchmod(fileno(f_merged), st_mode) != 0) {
  		err = got_error_from_errno2("fchmod", merged_path);
  		goto done;
  	}
  
  	if (rename(merged_path, ondisk_path) != 0) {
  		err = got_error_from_errno3("rename", merged_path,
  		    ondisk_path);
  		goto done;
  	}
  done:
  	if (err) {
  		if (merged_path)
  			unlink(merged_path);
  	}
  	if (merged_fd != -1 && close(merged_fd) == -1 && err == NULL)
  		err = got_error_from_errno("close");
  	if (f_merged && fclose(f_merged) == EOF && err == NULL)
  		err = got_error_from_errno("fclose");
  	free(merged_path);
  	free(base_path);
  	free(parent);
  	return err;
  }
  
  static const struct got_error *
  update_symlink(const char *ondisk_path, const char *target_path,
      size_t target_len)
  {
  	/* This is not atomic but matches what 'ln -sf' does. */
  	if (unlink(ondisk_path) == -1)
  		return got_error_from_errno2("unlink", ondisk_path);
  	if (symlink(target_path, ondisk_path) == -1)
  		return got_error_from_errno3("symlink", target_path,
  		    ondisk_path);
  	return NULL;
  }
  
  /*
   * Overwrite a symlink (or a regular file in case there was a "bad" symlink)
   * in the work tree with a file that contains conflict markers and the
   * conflicting target paths of the original version, a "derived version"
   * of a symlink from an incoming change, and a local version of the symlink.
   *
   * The original versions's target path can be NULL if it is not available,
   * such as if both derived versions added a new symlink at the same path.
   *
   * The incoming derived symlink target is NULL in case the incoming change
   * has deleted this symlink.
   */
  static const struct got_error *
  install_symlink_conflict(const char *deriv_target,
      struct got_object_id *deriv_base_commit_id, const char *orig_target,
      const char *label_orig, const char *local_target, const char *ondisk_path)
  {
  	const struct got_error *err;
  	char *id_str = NULL, *label_deriv = NULL, *path = NULL;
  	FILE *f = NULL;
  
  	err = got_object_id_str(&id_str, deriv_base_commit_id);
  	if (err)
  		return got_error_from_errno("asprintf");
  
  	if (asprintf(&label_deriv, "%s: commit %s",
  	    GOT_MERGE_LABEL_MERGED, id_str) == -1) {
  		err = got_error_from_errno("asprintf");
  		goto done;
  	}
  
  	err = got_opentemp_named(&path, &f, "got-symlink-conflict");
  	if (err)
  		goto done;
  
  	if (fchmod(fileno(f), GOT_DEFAULT_FILE_MODE) == -1) {
  		err = got_error_from_errno2("fchmod", path);
  		goto done;
  	}
  
  	if (fprintf(f, "%s %s\n%s\n%s%s%s%s%s\n%s\n%s\n",
  	    GOT_DIFF_CONFLICT_MARKER_BEGIN, label_deriv,
  	    deriv_target ? deriv_target : "(symlink was deleted)",
  	    orig_target ? label_orig : "",
  	    orig_target ? "\n" : "",
  	    orig_target ? orig_target : "",
  	    orig_target ? "\n" : "",
  	    GOT_DIFF_CONFLICT_MARKER_SEP,
  	    local_target, GOT_DIFF_CONFLICT_MARKER_END) < 0) {
  		err = got_error_from_errno2("fprintf", path);
  		goto done;
  	}
  
  	if (unlink(ondisk_path) == -1) {
  		err = got_error_from_errno2("unlink", ondisk_path);
  		goto done;
  	}
  	if (rename(path, ondisk_path) == -1) {
  		err = got_error_from_errno3("rename", path, ondisk_path);
  		goto done;
  	}
  done:
  	if (f != NULL && fclose(f) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", path);
  	free(path);
  	free(id_str);
  	free(label_deriv);
  	return err;
  }
  
  /* forward declaration */
  static const struct got_error *
  merge_blob(int *, struct got_worktree *, struct got_blob_object *,
      const char *, const char *, uint16_t, const char *,
      struct got_blob_object *, struct got_object_id *,
      struct got_repository *, got_worktree_checkout_cb, void *);
  
  /*
   * Merge a symlink into the work tree, where blob_orig acts as the common
   * ancestor, deriv_target is the link target of the first derived version,
   * and the symlink on disk acts as the second derived version.
   * Assume that contents of both blobs represent symlinks.
   */
  static const struct got_error *
  merge_symlink(struct got_worktree *worktree,
      struct got_blob_object *blob_orig, const char *ondisk_path,
      const char *path, const char *label_orig, const char *deriv_target,
      struct got_object_id *deriv_base_commit_id, struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	const struct got_error *err = NULL;
  	char *ancestor_target = NULL;
  	struct stat sb;
  	ssize_t ondisk_len, deriv_len;
  	char ondisk_target[PATH_MAX];
  	int have_local_change = 0;
  	int have_incoming_change = 0;
  
  	if (lstat(ondisk_path, &sb) == -1)
  		return got_error_from_errno2("lstat", ondisk_path);
  
  	ondisk_len = readlink(ondisk_path, ondisk_target,
  	    sizeof(ondisk_target));
  	if (ondisk_len == -1) {
  		err = got_error_from_errno2("readlink",
  		    ondisk_path);
  		goto done;
  	}
  	ondisk_target[ondisk_len] = '\0';
  
  	if (blob_orig) {
  		err = got_object_blob_read_to_str(&ancestor_target, blob_orig);
  		if (err)
  			goto done;
  	}
  
  	if (ancestor_target == NULL ||
  	    (ondisk_len != strlen(ancestor_target) ||
  	    memcmp(ondisk_target, ancestor_target, ondisk_len) != 0))
  		have_local_change = 1;
  
  	deriv_len = strlen(deriv_target);
  	if (ancestor_target == NULL ||
  	    (deriv_len != strlen(ancestor_target) ||
  	    memcmp(deriv_target, ancestor_target, deriv_len) != 0))
  		have_incoming_change = 1;
  
  	if (!have_local_change && !have_incoming_change) {
  		if (ancestor_target) {
  			/* Both sides made the same change. */
  			err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE,
  			    path);
  		} else if (deriv_len == ondisk_len &&
  		    memcmp(ondisk_target, deriv_target, deriv_len) == 0) {
  			/* Both sides added the same symlink. */
  			err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE,
  			    path);
  		} else {
  			/* Both sides added symlinks which don't match. */
  			err = install_symlink_conflict(deriv_target,
  			    deriv_base_commit_id, ancestor_target,
  			    label_orig, ondisk_target, ondisk_path);
  			if (err)
  				goto done;
  			err = (*progress_cb)(progress_arg, GOT_STATUS_CONFLICT,
  			    path);
  		}
  	} else if (!have_local_change && have_incoming_change) {
  		/* Apply the incoming change. */
  		err = update_symlink(ondisk_path, deriv_target,
  		    strlen(deriv_target));
  		if (err)
  			goto done;
  		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, path);
  	} else if (have_local_change && have_incoming_change) {
  		if (deriv_len == ondisk_len &&
  		    memcmp(deriv_target, ondisk_target, deriv_len) == 0) {
  			/* Both sides made the same change. */
  			err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE,
  			    path);
  		} else {
  			err = install_symlink_conflict(deriv_target,
  			    deriv_base_commit_id, ancestor_target, label_orig,
  			    ondisk_target, ondisk_path);
  			if (err)
  				goto done;
  			err = (*progress_cb)(progress_arg, GOT_STATUS_CONFLICT,
  			    path);
  		}
  	}
  
  done:
  	free(ancestor_target);
  	return err;
  }
  
  static const struct got_error *
  dump_symlink_target_path_to_file(FILE **outfile, const char *ondisk_path)
  {
  	const struct got_error *err = NULL;
  	char target_path[PATH_MAX];
  	ssize_t target_len;
  	size_t n;
  	FILE *f;
  
  	*outfile = NULL;
  
  	f = got_opentemp();
  	if (f == NULL)
  		return got_error_from_errno("got_opentemp");
  	target_len = readlink(ondisk_path, target_path, sizeof(target_path));
  	if (target_len == -1) {
  		err = got_error_from_errno2("readlink", ondisk_path);
  		goto done;
  	}
  	n = fwrite(target_path, 1, target_len, f);
  	if (n != target_len) {
  		err = got_ferror(f, GOT_ERR_IO);
  		goto done;
  	}
  	if (fflush(f) == EOF) {
  		err = got_error_from_errno("fflush");
  		goto done;
  	}
  	if (fseek(f, 0L, SEEK_SET) == -1) {
  		err = got_ferror(f, GOT_ERR_IO);
  		goto done;
  	}
  done:
  	if (err)
  		fclose(f);
  	else
  		*outfile = f;
  	return err;
  }
  
  /*
   * Perform a 3-way merge where blob_orig acts as the common ancestor,
   * blob_deriv acts as the first derived version, and the file on disk
   * acts as the second derived version.
   */
  static const struct got_error *
  merge_blob(int *local_changes_subsumed, struct got_worktree *worktree,
      struct got_blob_object *blob_orig, const char *ondisk_path,
      const char *path, uint16_t st_mode, const char *label_orig,
      struct got_blob_object *blob_deriv,
      struct got_object_id *deriv_base_commit_id, struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	const struct got_error *err = NULL;
  	FILE *f_orig = NULL, *f_deriv = NULL, *f_deriv2 = NULL;
  	char *blob_orig_path = NULL;
  	char *blob_deriv_path = NULL, *base_path = NULL, *id_str = NULL;
  	char *label_deriv = NULL, *parent = NULL;
  
  	*local_changes_subsumed = 0;
  
  	err = got_path_dirname(&parent, ondisk_path);
  	if (err)
  		return err;
  
  	if (blob_orig) {
  		if (asprintf(&base_path, "%s/got-merge-blob-orig",
  		    parent) == -1) {
  			err = got_error_from_errno("asprintf");
  			base_path = NULL;
  			goto done;
  		}
  
  		err = got_opentemp_named(&blob_orig_path, &f_orig, base_path);
  		if (err)
  			goto done;
  		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f_orig,
  		    blob_orig);
  		if (err)
  			goto done;
  		free(base_path);
  	} else {
  		/*
  		 * No common ancestor exists. This is an "add vs add" conflict
  		 * and we simply use an empty ancestor file to make both files
  		 * appear in the merged result in their entirety.
  		 */
  		f_orig = got_opentemp();
  		if (f_orig == NULL) {
  			err = got_error_from_errno("got_opentemp");
  			goto done;
  		}
  	}
  
  	if (asprintf(&base_path, "%s/got-merge-blob-deriv", parent) == -1) {
  		err = got_error_from_errno("asprintf");
  		base_path = NULL;
  		goto done;
  	}
  
  	err = got_opentemp_named(&blob_deriv_path, &f_deriv, base_path);
  	if (err)
  		goto done;
  	err = got_object_blob_dump_to_file(NULL, NULL, NULL, f_deriv,
  	    blob_deriv);
  	if (err)
  		goto done;
  
  	err = got_object_id_str(&id_str, deriv_base_commit_id);
  	if (err)
  		goto done;
  	if (asprintf(&label_deriv, "%s: commit %s",
  	    GOT_MERGE_LABEL_MERGED, id_str) == -1) {
  		err = got_error_from_errno("asprintf");
  		goto done;
  	}
  
  	/* 
  	 * In order the run a 3-way merge with a symlink we copy the symlink's
  	 * target path into a temporary file and use that file with diff3.
  	 */
  	if (S_ISLNK(st_mode)) {
  		err = dump_symlink_target_path_to_file(&f_deriv2, ondisk_path);
  		if (err)
  			goto done;
  	} else {
  		int fd;
  		fd = open(ondisk_path, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
  		if (fd == -1) {
  			err = got_error_from_errno2("open", ondisk_path);
  			goto done;
  		}
  		f_deriv2 = fdopen(fd, "r");
  		if (f_deriv2 == NULL) {
  			err = got_error_from_errno2("fdopen", ondisk_path);
  			close(fd);
  			goto done;
  		}
  	}
  
  	err = merge_file(local_changes_subsumed, worktree, f_orig, f_deriv,
  	    f_deriv2, ondisk_path, path, st_mode, label_orig, label_deriv,
  	    NULL, GOT_DIFF_ALGORITHM_MYERS, repo, progress_cb, progress_arg);
  done:
  	if (f_orig && fclose(f_orig) == EOF && err == NULL)
  		err = got_error_from_errno("fclose");
  	if (f_deriv && fclose(f_deriv) == EOF && err == NULL)
  		err = got_error_from_errno("fclose");
  	if (f_deriv2 && fclose(f_deriv2) == EOF && err == NULL)
  		err = got_error_from_errno("fclose");
  	free(base_path);
  	if (blob_orig_path) {
  		unlink(blob_orig_path);
  		free(blob_orig_path);
  	}
  	if (blob_deriv_path) {
  		unlink(blob_deriv_path);
  		free(blob_deriv_path);
  	}
  	free(id_str);
  	free(label_deriv);
  	free(parent);
  	return err;
  }
  
  static const struct got_error *
  create_fileindex_entry(struct got_fileindex_entry **new_iep,
      struct got_fileindex *fileindex, struct got_object_id *base_commit_id,
      int wt_fd, const char *path, struct got_object_id *blob_id)
  {
  	const struct got_error *err = NULL;
  	struct got_fileindex_entry *new_ie;
  
  	*new_iep = NULL;
  
  	err = got_fileindex_entry_alloc(&new_ie, path);
  	if (err)
  		return err;
  
  	err = got_fileindex_entry_update(new_ie, wt_fd, path,
  	    blob_id->sha1, base_commit_id->sha1, 1);
  	if (err)
  		goto done;
  
  	err = got_fileindex_entry_add(fileindex, new_ie);
  done:
  	if (err)
  		got_fileindex_entry_free(new_ie);
  	else
  		*new_iep = new_ie;
  	return err;
  }
  
  static mode_t
  get_ondisk_perms(int executable, mode_t st_mode)
  {
  	mode_t xbits = S_IXUSR;
  
  	if (executable) {
  		/* Map read bits to execute bits. */
  		if (st_mode & S_IRGRP)
  			xbits |= S_IXGRP;
  		if (st_mode & S_IROTH)
  			xbits |= S_IXOTH;
  		return st_mode | xbits;
  	}
  
  	return (st_mode & ~(S_IXUSR | S_IXGRP | S_IXOTH));
  }
  
  /* forward declaration */
  static const struct got_error *
  install_blob(struct got_worktree *worktree, const char *ondisk_path,
      const char *path, mode_t te_mode, mode_t st_mode,
      struct got_blob_object *blob, int restoring_missing_file,
      int reverting_versioned_file, int installing_bad_symlink,
      int path_is_unversioned, struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg);
  
  /*
   * This function assumes that the provided symlink target points at a
   * safe location in the work tree!
   */
  static const struct got_error *
  replace_existing_symlink(int *did_something, const char *ondisk_path,
      const char *target_path, size_t target_len)
  {
  	const struct got_error *err = NULL;
  	ssize_t elen;
  	char etarget[PATH_MAX];
  	int fd;
  
  	*did_something = 0;
  
  	/*
  	 * "Bad" symlinks (those pointing outside the work tree or into the
  	 * .got directory) are installed in the work tree as a regular file
  	 * which contains the bad symlink target path.
  	 * The new symlink target has already been checked for safety by our
  	 * caller. If we can successfully open a regular file then we simply
  	 * replace this file with a symlink below.
  	 */
  	fd = open(ondisk_path, O_RDWR | O_EXCL | O_NOFOLLOW | O_CLOEXEC);
  	if (fd == -1) {
  		if (!got_err_open_nofollow_on_symlink())
  			return got_error_from_errno2("open", ondisk_path);
  
  		/* We are updating an existing on-disk symlink. */
  		elen = readlink(ondisk_path, etarget, sizeof(etarget));
  		if (elen == -1)
  			return got_error_from_errno2("readlink", ondisk_path);
  
  		if (elen == target_len &&
  		    memcmp(etarget, target_path, target_len) == 0)
  			return NULL; /* nothing to do */
  	}
  
  	*did_something = 1;
  	err = update_symlink(ondisk_path, target_path, target_len);
  	if (fd != -1 && close(fd) == -1 && err == NULL)
  		err = got_error_from_errno2("close", ondisk_path);
  	return err;
  }
  
  static const struct got_error *
  is_bad_symlink_target(int *is_bad_symlink, const char *target_path,
      size_t target_len, const char *ondisk_path, const char *wtroot_path)
  {
  	const struct got_error *err = NULL;
  	char canonpath[PATH_MAX];
  	char *path_got = NULL;
  
  	*is_bad_symlink = 0;
  
  	if (target_len >= sizeof(canonpath)) {
  		*is_bad_symlink = 1;
  		return NULL;
  	}
  
  	/*
  	 * We do not use realpath(3) to resolve the symlink's target
  	 * path because we don't want to resolve symlinks recursively.
  	 * Instead we make the path absolute and then canonicalize it.
  	 * Relative symlink target lookup should begin at the directory
  	 * in which the blob object is being installed.
  	 */
  	if (!got_path_is_absolute(target_path)) {
  		char *abspath, *parent;
  		err = got_path_dirname(&parent, ondisk_path);
  		if (err)
  			return err;
  		if (asprintf(&abspath, "%s/%s",  parent, target_path) == -1) {
  			free(parent);
  			return got_error_from_errno("asprintf");
  		}
  		free(parent);
  		if (strlen(abspath) >= sizeof(canonpath)) {
  			err = got_error_path(abspath, GOT_ERR_BAD_PATH);
  			free(abspath);
  			return err;
  		}
  		err = got_canonpath(abspath, canonpath, sizeof(canonpath));
  		free(abspath);
  		if (err)
  			return err;
  	} else {
  		err = got_canonpath(target_path, canonpath, sizeof(canonpath));
  		if (err)
  			return err;
  	}
  
  	/* Only allow symlinks pointing at paths within the work tree. */
  	if (!got_path_is_child(canonpath, wtroot_path, strlen(wtroot_path))) {
  		*is_bad_symlink = 1;
  		return NULL;
  	}
  
  	/* Do not allow symlinks pointing into the .got directory. */
  	if (asprintf(&path_got, "%s/%s", wtroot_path,
  	    GOT_WORKTREE_GOT_DIR) == -1)
  		return got_error_from_errno("asprintf");
  	if (got_path_is_child(canonpath, path_got, strlen(path_got)))
  		*is_bad_symlink = 1;
  
  	free(path_got);
  	return NULL;
  }
  
  static const struct got_error *
  install_symlink(int *is_bad_symlink, struct got_worktree *worktree,
      const char *ondisk_path, const char *path, struct got_blob_object *blob,
      int restoring_missing_file, int reverting_versioned_file,
      int path_is_unversioned, int allow_bad_symlinks,
      struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	const struct got_error *err = NULL;
  	char target_path[PATH_MAX];
  	size_t len, target_len = 0;
  	char *path_got = NULL;
  	const uint8_t *buf = got_object_blob_get_read_buf(blob);
  	size_t hdrlen = got_object_blob_get_hdrlen(blob);
  
  	*is_bad_symlink = 0;
  
  	/* 
  	 * Blob object content specifies the target path of the link.
  	 * If a symbolic link cannot be installed we instead create
  	 * a regular file which contains the link target path stored
  	 * in the blob object.
  	 */
  	do {
  		err = got_object_blob_read_block(&len, blob);
  		if (len + target_len >= sizeof(target_path)) {
  			/* Path too long; install as a regular file. */
  			*is_bad_symlink = 1;
  			got_object_blob_rewind(blob);
  			return install_blob(worktree, ondisk_path, path,
  			    GOT_DEFAULT_FILE_MODE, GOT_DEFAULT_FILE_MODE, blob,
  			    restoring_missing_file, reverting_versioned_file,
  			    1, path_is_unversioned, repo, progress_cb,
  			    progress_arg);
  		}
  		if (len > 0) {
  			/* Skip blob object header first time around. */
  			memcpy(target_path + target_len, buf + hdrlen,
  			    len - hdrlen);
  			target_len += len - hdrlen;
  			hdrlen = 0;
  		}
  	} while (len != 0);
  	target_path[target_len] = '\0';
  
  	err = is_bad_symlink_target(is_bad_symlink, target_path, target_len,
  	    ondisk_path, worktree->root_path);
  	if (err)
  		return err;
  
  	if (*is_bad_symlink && !allow_bad_symlinks) {
  		/* install as a regular file */
  		got_object_blob_rewind(blob);
  		err = install_blob(worktree, ondisk_path, path,
  		    GOT_DEFAULT_FILE_MODE, GOT_DEFAULT_FILE_MODE, blob,
  		    restoring_missing_file, reverting_versioned_file, 1,
  		    path_is_unversioned, repo, progress_cb, progress_arg);
  		goto done;
  	}
  
  	if (symlink(target_path, ondisk_path) == -1) {
  		if (errno == EEXIST) {
  			int symlink_replaced;
  			if (path_is_unversioned) {
  				err = (*progress_cb)(progress_arg,
  				    GOT_STATUS_UNVERSIONED, path);
  				goto done;
  			}
  			err = replace_existing_symlink(&symlink_replaced,
  			    ondisk_path, target_path, target_len);
  			if (err)
  				goto done;
  			if (progress_cb) {
  				if (symlink_replaced) {
  					err = (*progress_cb)(progress_arg,
  					    reverting_versioned_file ?
  					    GOT_STATUS_REVERT :
  					    GOT_STATUS_UPDATE, path);
  				} else {
  					err = (*progress_cb)(progress_arg,
  					    GOT_STATUS_EXISTS, path);
  				}
  			}
  			goto done; /* Nothing else to do. */
  		}
  
  		if (errno == ENOENT) {
  			char *parent;
  			err = got_path_dirname(&parent, ondisk_path);
  			if (err)
  				goto done;
  			err = add_dir_on_disk(worktree, parent);
  			free(parent);
  			if (err)
  				goto done;
  			/*
  			 * Retry, and fall through to error handling
  			 * below if this second attempt fails.
  			 */
  			if (symlink(target_path, ondisk_path) != -1) {
  				err = NULL; /* success */
  				goto done;
  			}
  		}
  
  		/* Handle errors from first or second creation attempt. */
  		if (errno == ENAMETOOLONG) {
  			/* bad target path; install as a regular file */
  			*is_bad_symlink = 1;
  			got_object_blob_rewind(blob);
  			err = install_blob(worktree, ondisk_path, path,
  			    GOT_DEFAULT_FILE_MODE, GOT_DEFAULT_FILE_MODE, blob,
  			    restoring_missing_file, reverting_versioned_file, 1,
  			    path_is_unversioned, repo,
  			    progress_cb, progress_arg);
  		} else if (errno == ENOTDIR) {
  			err = got_error_path(ondisk_path,
  			    GOT_ERR_FILE_OBSTRUCTED);
  		} else {
  			err = got_error_from_errno3("symlink",
  			    target_path, ondisk_path);
  		}
  	} else if (progress_cb)
  		err = (*progress_cb)(progress_arg, reverting_versioned_file ?
  		    GOT_STATUS_REVERT : GOT_STATUS_ADD, path);
  done:
  	free(path_got);
  	return err;
  }
  
  static const struct got_error *
  install_blob(struct got_worktree *worktree, const char *ondisk_path,
      const char *path, mode_t te_mode, mode_t st_mode,
      struct got_blob_object *blob, int restoring_missing_file,
      int reverting_versioned_file, int installing_bad_symlink,
      int path_is_unversioned, struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	const struct got_error *err = NULL;
  	int fd = -1;
  	size_t len, hdrlen;
  	int update = 0;
  	char *tmppath = NULL;
  
  	fd = open(ondisk_path, O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW |
  	    O_CLOEXEC, GOT_DEFAULT_FILE_MODE);
  	if (fd == -1) {
  		if (errno == ENOENT) {
  			char *parent;
  			err = got_path_dirname(&parent, path);
  			if (err)
  				return err;
  			err = add_dir_on_disk(worktree, parent);
  			free(parent);
  			if (err)
  				return err;
  			fd = open(ondisk_path,
  			    O_RDWR | O_CREAT | O_EXCL | O_NOFOLLOW | O_CLOEXEC,
  			    GOT_DEFAULT_FILE_MODE);
  			if (fd == -1)
  				return got_error_from_errno2("open",
  				    ondisk_path);
  		} else if (errno == EEXIST) {
  			if (path_is_unversioned) {
  				err = (*progress_cb)(progress_arg,
  				    GOT_STATUS_UNVERSIONED, path);
  				goto done;
  			}
  			if (!(S_ISLNK(st_mode) && S_ISREG(te_mode)) &&
  			    !S_ISREG(st_mode) && !installing_bad_symlink) {
  				/* TODO file is obstructed; do something */
  				err = got_error_path(ondisk_path,
  				    GOT_ERR_FILE_OBSTRUCTED);
  				goto done;
  			} else {
  				err = got_opentemp_named_fd(&tmppath, &fd,
  				    ondisk_path);
  				if (err)
  					goto done;
  				update = 1;
  			}
  		} else
  			return got_error_from_errno2("open", ondisk_path);
  	}
  
  	if (fchmod(fd, get_ondisk_perms(te_mode & S_IXUSR, st_mode)) == -1) {
  		err = got_error_from_errno2("fchmod",
  		    update ? tmppath : ondisk_path);
  		goto done;
  	}
  
  	if (progress_cb) {
  		if (restoring_missing_file)
  			err = (*progress_cb)(progress_arg, GOT_STATUS_MISSING,
  			    path);
  		else if (reverting_versioned_file)
  			err = (*progress_cb)(progress_arg, GOT_STATUS_REVERT,
  			    path);
  		else
  			err = (*progress_cb)(progress_arg,
  			    update ? GOT_STATUS_UPDATE : GOT_STATUS_ADD, path);
  		if (err)
  			goto done;
  	}
  
  	hdrlen = got_object_blob_get_hdrlen(blob);
  	do {
  		const uint8_t *buf = got_object_blob_get_read_buf(blob);
  		err = got_object_blob_read_block(&len, blob);
  		if (err)
  			break;
  		if (len > 0) {
  			/* Skip blob object header first time around. */
  			ssize_t outlen = write(fd, buf + hdrlen, len - hdrlen);
  			if (outlen == -1) {
  				err = got_error_from_errno("write");
  				goto done;
  			} else if (outlen != len - hdrlen) {
  				err = got_error(GOT_ERR_IO);
  				goto done;
  			}
  			hdrlen = 0;
  		}
  	} while (len != 0);
  
  	if (fsync(fd) != 0) {
  		err = got_error_from_errno("fsync");
  		goto done;
  	}
  
  	if (update) {
  		if (S_ISLNK(st_mode) && unlink(ondisk_path) == -1) {
  			err = got_error_from_errno2("unlink", ondisk_path);
  			goto done;
  		}
  		if (rename(tmppath, ondisk_path) != 0) {
  			err = got_error_from_errno3("rename", tmppath,
  			    ondisk_path);
  			goto done;
  		}
  		free(tmppath);
  		tmppath = NULL;
  	}
  
  done:
  	if (fd != -1 && close(fd) == -1 && err == NULL)
  		err = got_error_from_errno("close");
  	if (tmppath != NULL && unlink(tmppath) == -1 && err == NULL)
  		err = got_error_from_errno2("unlink", tmppath);
  	free(tmppath);
  	return err;
  }
  
  /* Upgrade STATUS_MODIFY to STATUS_CONFLICT if a conflict marker is found. */
  static const struct got_error *
  get_modified_file_content_status(unsigned char *status, FILE *f)
  {
  	const struct got_error *err = NULL;
  	const char *markers[3] = {
  		GOT_DIFF_CONFLICT_MARKER_BEGIN,
  		GOT_DIFF_CONFLICT_MARKER_SEP,
  		GOT_DIFF_CONFLICT_MARKER_END
  	};
  	int i = 0;
  	char *line = NULL;
  	size_t linesize = 0;
  	ssize_t linelen;
  
  	while (*status == GOT_STATUS_MODIFY) {
  		linelen = getline(&line, &linesize, f);
  		if (linelen == -1) {
  			if (feof(f))
  				break;
  			err = got_ferror(f, GOT_ERR_IO);
  			break;
  		}
  
  		if (strncmp(line, markers[i], strlen(markers[i])) == 0) {
  			if (strcmp(markers[i], GOT_DIFF_CONFLICT_MARKER_END)
  			    == 0)
  				*status = GOT_STATUS_CONFLICT;
  			else
  				i++;
  		}
  	}
  	free(line);
  
  	return err;
  }
  
  static int
  xbit_differs(struct got_fileindex_entry *ie, uint16_t st_mode)
  {
  	mode_t ie_mode = got_fileindex_perms_to_st(ie);
  	return ((ie_mode & S_IXUSR) != (st_mode & S_IXUSR));
  }
  
  static int
  stat_info_differs(struct got_fileindex_entry *ie, struct stat *sb)
  {
  	return !(ie->ctime_sec == sb->st_ctim.tv_sec &&
  	    ie->ctime_nsec == sb->st_ctim.tv_nsec &&
  	    ie->mtime_sec == sb->st_mtim.tv_sec &&
  	    ie->mtime_nsec == sb->st_mtim.tv_nsec &&
  	    ie->size == (sb->st_size & 0xffffffff) &&
  	    !xbit_differs(ie, sb->st_mode));
  }
  
  static unsigned char
  get_staged_status(struct got_fileindex_entry *ie)
  {
  	switch (got_fileindex_entry_stage_get(ie)) {
  	case GOT_FILEIDX_STAGE_ADD:
  		return GOT_STATUS_ADD;
  	case GOT_FILEIDX_STAGE_DELETE:
  		return GOT_STATUS_DELETE;
  	case GOT_FILEIDX_STAGE_MODIFY:
  		return GOT_STATUS_MODIFY;
  	default:
  		return GOT_STATUS_NO_CHANGE;
  	}
  }
  
  static const struct got_error *
  get_symlink_modification_status(unsigned char *status,
      struct got_fileindex_entry *ie, const char *abspath,
      int dirfd, const char *de_name, struct got_blob_object *blob)
  {
  	const struct got_error *err = NULL;
  	char target_path[PATH_MAX];
  	char etarget[PATH_MAX];
  	ssize_t elen;
  	size_t len, target_len = 0;
  	const uint8_t *buf = got_object_blob_get_read_buf(blob);
  	size_t hdrlen = got_object_blob_get_hdrlen(blob);
  
  	*status = GOT_STATUS_NO_CHANGE;
  
  	/* Blob object content specifies the target path of the link. */
  	do {
  		err = got_object_blob_read_block(&len, blob);
  		if (err)
  			return err;
  		if (len + target_len >= sizeof(target_path)) {
  			/*
  			 * Should not happen. The blob contents were OK
  			 * when this symlink was installed.
  			 */
  			return got_error(GOT_ERR_NO_SPACE);
  		}
  		if (len > 0) {
  			/* Skip blob object header first time around. */
  			memcpy(target_path + target_len, buf + hdrlen,
  			    len - hdrlen);
  			target_len += len - hdrlen;
  			hdrlen = 0;
  		}
  	} while (len != 0);
  	target_path[target_len] = '\0';
  
  	if (dirfd != -1) {
  		elen = readlinkat(dirfd, de_name, etarget, sizeof(etarget));
  		if (elen == -1)
  			return got_error_from_errno2("readlinkat", abspath);
  	} else {
  		elen = readlink(abspath, etarget, sizeof(etarget));
  		if (elen == -1)
  			return got_error_from_errno2("readlink", abspath);
  	}
  
  	if (elen != target_len || memcmp(etarget, target_path, target_len) != 0)
  		*status = GOT_STATUS_MODIFY;
  
  	return NULL;
  }
  
  static const struct got_error *
  get_file_status(unsigned char *status, struct stat *sb,
      struct got_fileindex_entry *ie, const char *abspath,
      int dirfd, const char *de_name, struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	struct got_object_id id;
  	size_t hdrlen;
  	int fd = -1;
  	FILE *f = NULL;
  	uint8_t fbuf[8192];
  	struct got_blob_object *blob = NULL;
  	size_t flen, blen;
  	unsigned char staged_status = get_staged_status(ie);
  
  	*status = GOT_STATUS_NO_CHANGE;
  	memset(sb, 0, sizeof(*sb));
  
  	/*
  	 * Whenever the caller provides a directory descriptor and a
  	 * directory entry name for the file, use them! This prevents
  	 * race conditions if filesystem paths change beneath our feet.
  	 */
  	if (dirfd != -1) {
  		if (fstatat(dirfd, de_name, sb, AT_SYMLINK_NOFOLLOW) == -1) {
  			if (errno == ENOENT) {
  				if (got_fileindex_entry_has_file_on_disk(ie))
  					*status = GOT_STATUS_MISSING;
  				else
  					*status = GOT_STATUS_DELETE;
  				goto done;
  			}
  			err = got_error_from_errno2("fstatat", abspath);
  			goto done;
  		}
  	} else {
  		fd = open(abspath, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
  		if (fd == -1 && errno != ENOENT &&
  		    !got_err_open_nofollow_on_symlink())
  			return got_error_from_errno2("open", abspath);
  		else if (fd == -1 && got_err_open_nofollow_on_symlink()) {
  			if (lstat(abspath, sb) == -1)
  				return got_error_from_errno2("lstat", abspath);
  		} else if (fd == -1 || fstat(fd, sb) == -1) {
  			if (errno == ENOENT) {
  				if (got_fileindex_entry_has_file_on_disk(ie))
  					*status = GOT_STATUS_MISSING;
  				else
  					*status = GOT_STATUS_DELETE;
  				goto done;
  			}
  			err = got_error_from_errno2("fstat", abspath);
  			goto done;
  		}
  	}
  
  	if (!S_ISREG(sb->st_mode) && !S_ISLNK(sb->st_mode)) {
  		*status = GOT_STATUS_OBSTRUCTED;
  		goto done;
  	}
  
  	if (!got_fileindex_entry_has_file_on_disk(ie)) {
  		*status = GOT_STATUS_DELETE;
  		goto done;
  	} else if (!got_fileindex_entry_has_blob(ie) &&
  	    staged_status != GOT_STATUS_ADD) {
  		*status = GOT_STATUS_ADD;
  		goto done;
  	}
  
  	if (!stat_info_differs(ie, sb))
  		goto done;
  
  	if (S_ISLNK(sb->st_mode) &&
  	    got_fileindex_entry_filetype_get(ie) != GOT_FILEIDX_MODE_SYMLINK) {
  		*status = GOT_STATUS_MODIFY;
  		goto done;
  	}
  
  	if (staged_status == GOT_STATUS_MODIFY ||
  	    staged_status == GOT_STATUS_ADD)
  		memcpy(id.sha1, ie->staged_blob_sha1, sizeof(id.sha1));
  	else
  		memcpy(id.sha1, ie->blob_sha1, sizeof(id.sha1));
  
  	err = got_object_open_as_blob(&blob, repo, &id, sizeof(fbuf));
  	if (err)
  		goto done;
  
  	if (S_ISLNK(sb->st_mode)) {
  		err = get_symlink_modification_status(status, ie,
  		    abspath, dirfd, de_name, blob);
  		goto done;
  	}
  
  	if (dirfd != -1) {
  		fd = openat(dirfd, de_name, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
  		if (fd == -1) {
  			err = got_error_from_errno2("openat", abspath);
  			goto done;
  		}
  	}
  
  	f = fdopen(fd, "r");
  	if (f == NULL) {
  		err = got_error_from_errno2("fdopen", abspath);
  		goto done;
  	}
  	fd = -1;
  	hdrlen = got_object_blob_get_hdrlen(blob);
  	for (;;) {
  		const uint8_t *bbuf = got_object_blob_get_read_buf(blob);
  		err = got_object_blob_read_block(&blen, blob);
  		if (err)
  			goto done;
  		/* Skip length of blob object header first time around. */
  		flen = fread(fbuf, 1, sizeof(fbuf) - hdrlen, f);
  		if (flen == 0 && ferror(f)) {
  			err = got_error_from_errno("fread");
  			goto done;
  		}
  		if (blen - hdrlen == 0) {
  			if (flen != 0)
  				*status = GOT_STATUS_MODIFY;
  			break;
  		} else if (flen == 0) {
  			if (blen - hdrlen != 0)
  				*status = GOT_STATUS_MODIFY;
  			break;
  		} else if (blen - hdrlen == flen) {
  			/* Skip blob object header first time around. */
  			if (memcmp(bbuf + hdrlen, fbuf, flen) != 0) {
  				*status = GOT_STATUS_MODIFY;
  				break;
  			}
  		} else {
  			*status = GOT_STATUS_MODIFY;
  			break;
  		}
  		hdrlen = 0;
  	}
  
  	if (*status == GOT_STATUS_MODIFY) {
  		rewind(f);
  		err = get_modified_file_content_status(status, f);
  	} else if (xbit_differs(ie, sb->st_mode))
  		*status = GOT_STATUS_MODE_CHANGE;
  done:
  	if (blob)
  		got_object_blob_close(blob);
  	if (f != NULL && fclose(f) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", abspath);
  	if (fd != -1 && close(fd) == -1 && err == NULL)
  		err = got_error_from_errno2("close", abspath);
  	return err;
  }
  
  /*
   * Update timestamps in the file index if a file is unmodified and
   * we had to run a full content comparison to find out.
   */
  static const struct got_error *
  sync_timestamps(int wt_fd, const char *path, unsigned char status,
      struct got_fileindex_entry *ie, struct stat *sb)
  {
  	if (status == GOT_STATUS_NO_CHANGE && stat_info_differs(ie, sb))
  		return got_fileindex_entry_update(ie, wt_fd, path,
  		    ie->blob_sha1, ie->commit_sha1, 1);
  
  	return NULL;
  }
  
  static const struct got_error *
  update_blob(struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_fileindex_entry *ie,
      struct got_tree_entry *te, const char *path,
      struct got_repository *repo, got_worktree_checkout_cb progress_cb,
      void *progress_arg)
  {
  	const struct got_error *err = NULL;
  	struct got_blob_object *blob = NULL;
  	char *ondisk_path;
  	unsigned char status = GOT_STATUS_NO_CHANGE;
  	struct stat sb;
  
  	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, path) == -1)
  		return got_error_from_errno("asprintf");
  
  	if (ie) {
  		if (get_staged_status(ie) != GOT_STATUS_NO_CHANGE) {
  			err = got_error_path(ie->path, GOT_ERR_FILE_STAGED);
  			goto done;
  		}
  		err = get_file_status(&status, &sb, ie, ondisk_path, -1, NULL,
  		    repo);
  		if (err)
  			goto done;
  		if (status == GOT_STATUS_MISSING || status == GOT_STATUS_DELETE)
  			sb.st_mode = got_fileindex_perms_to_st(ie);
  	} else {
  		if (stat(ondisk_path, &sb) == -1) {
  			if (errno != ENOENT) {
  				err = got_error_from_errno2("stat",
  				    ondisk_path);
  				goto done;
  			}
  			sb.st_mode = GOT_DEFAULT_FILE_MODE;
  			status = GOT_STATUS_UNVERSIONED;
  		} else {
  			if (S_ISREG(sb.st_mode) || S_ISLNK(sb.st_mode))
  				status = GOT_STATUS_UNVERSIONED;
  			else
  				status = GOT_STATUS_OBSTRUCTED;
  		}
  	}
  
  	if (status == GOT_STATUS_OBSTRUCTED) {
  		if (ie)
  			got_fileindex_entry_mark_skipped(ie);
  		err = (*progress_cb)(progress_arg, status, path);
  		goto done;
  	}
  	if (status == GOT_STATUS_CONFLICT) {
  		if (ie)
  			got_fileindex_entry_mark_skipped(ie);
  		err = (*progress_cb)(progress_arg, GOT_STATUS_CANNOT_UPDATE,
  		    path);
  		goto done;
  	}
  
  	if (ie && status != GOT_STATUS_MISSING && S_ISREG(sb.st_mode) &&
  	    (S_ISLNK(te->mode) ||
  	    (te->mode & S_IXUSR) == (sb.st_mode & S_IXUSR))) {
  		/*
  		 * This is a regular file or an installed bad symlink.
  		 * If the file index indicates that this file is already
  		 * up-to-date with respect to the repository we can skip
  		 * updating contents of this file.
  		 */
  		if (got_fileindex_entry_has_commit(ie) &&
  		    memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
  		    SHA1_DIGEST_LENGTH) == 0) {
  			/* Same commit. */
  			err = sync_timestamps(worktree->root_fd,
  			    path, status, ie, &sb);
  			if (err)
  				goto done;
  			err = (*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
  			    path);
  			goto done;
  		}
  		if (got_fileindex_entry_has_blob(ie) &&
  		    memcmp(ie->blob_sha1, te->id.sha1,
  		    SHA1_DIGEST_LENGTH) == 0) {
  			/* Different commit but the same blob. */
  			err = sync_timestamps(worktree->root_fd,
  			    path, status, ie, &sb);
  			if (err)
  				goto done;
  			err = (*progress_cb)(progress_arg, GOT_STATUS_EXISTS,
  			    path);
  			goto done;
  		}
  	}
  
  	err = got_object_open_as_blob(&blob, repo, &te->id, 8192);
  	if (err)
  		goto done;
  
  	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_ADD) {
  		int update_timestamps;
  		struct got_blob_object *blob2 = NULL;
  		char *label_orig = NULL;
  		if (got_fileindex_entry_has_blob(ie)) {
  			struct got_object_id id2;
  			memcpy(id2.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
  			err = got_object_open_as_blob(&blob2, repo, &id2, 8192);
  			if (err)
  				goto done;
  		}
  		if (got_fileindex_entry_has_commit(ie)) {
  			char id_str[SHA1_DIGEST_STRING_LENGTH];
  			if (got_sha1_digest_to_str(ie->commit_sha1, id_str,
  			    sizeof(id_str)) == NULL) {
  				err = got_error_path(id_str,
  				    GOT_ERR_BAD_OBJ_ID_STR);
  				goto done;
  			}
  			if (asprintf(&label_orig, "%s: commit %s",
  			    GOT_MERGE_LABEL_BASE, id_str) == -1) {
  				err = got_error_from_errno("asprintf");
  				goto done;
  			}
  		}
  		if (S_ISLNK(te->mode) && S_ISLNK(sb.st_mode)) {
  			char *link_target;
  			err = got_object_blob_read_to_str(&link_target, blob);
  			if (err)
  				goto done;
  			err = merge_symlink(worktree, blob2, ondisk_path, path,
  			    label_orig, link_target, worktree->base_commit_id,
  			    repo, progress_cb, progress_arg);
  			free(link_target);
  		} else {
  			err = merge_blob(&update_timestamps, worktree, blob2,
  			    ondisk_path, path, sb.st_mode, label_orig, blob,
  			    worktree->base_commit_id, repo,
  			    progress_cb, progress_arg);
  		}
  		free(label_orig);
  		if (blob2)
  			got_object_blob_close(blob2);
  		if (err)
  			goto done;
  		/*
  		 * Do not update timestamps of files with local changes.
  		 * Otherwise, a future status walk would treat them as
  		 * unmodified files again.
  		 */
  		err = got_fileindex_entry_update(ie, worktree->root_fd, path,
  		    blob->id.sha1, worktree->base_commit_id->sha1,
  		    update_timestamps);
  	} else if (status == GOT_STATUS_MODE_CHANGE) {
  		err = got_fileindex_entry_update(ie, worktree->root_fd, path,
  		    blob->id.sha1, worktree->base_commit_id->sha1, 0);
  	} else if (status == GOT_STATUS_DELETE) {
  		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, path);
  		if (err)
  			goto done;
  		err = got_fileindex_entry_update(ie, worktree->root_fd, path,
  		    blob->id.sha1, worktree->base_commit_id->sha1, 0);
  		if (err)
  			goto done;
  	} else {
  		int is_bad_symlink = 0;
  		if (S_ISLNK(te->mode)) {
  			err = install_symlink(&is_bad_symlink, worktree,
  			    ondisk_path, path, blob,
  			    status == GOT_STATUS_MISSING, 0,
  			    status == GOT_STATUS_UNVERSIONED, 0,
  			    repo, progress_cb, progress_arg);
  		} else {
  			err = install_blob(worktree, ondisk_path, path,
  			    te->mode, sb.st_mode, blob,
  			    status == GOT_STATUS_MISSING, 0, 0,
  			    status == GOT_STATUS_UNVERSIONED, repo,
  			    progress_cb, progress_arg);
  		}
  		if (err)
  			goto done;
  
  		if (ie) {
  			err = got_fileindex_entry_update(ie,
  			    worktree->root_fd, path, blob->id.sha1,
  			    worktree->base_commit_id->sha1, 1);
  		} else {
  			err = create_fileindex_entry(&ie, fileindex,
  			    worktree->base_commit_id, worktree->root_fd, path,
  			    &blob->id);
  		}
  		if (err)
  			goto done;
  
  		if (is_bad_symlink) {
  			got_fileindex_entry_filetype_set(ie,
  			    GOT_FILEIDX_MODE_BAD_SYMLINK);
  		}
  	}
  	got_object_blob_close(blob);
  done:
  	free(ondisk_path);
  	return err;
  }
  
  static const struct got_error *
  remove_ondisk_file(const char *root_path, const char *path)
  {
  	const struct got_error *err = NULL;
  	char *ondisk_path = NULL, *parent = NULL;
  
  	if (asprintf(&ondisk_path, "%s/%s", root_path, path) == -1)
  		return got_error_from_errno("asprintf");
  
  	if (unlink(ondisk_path) == -1) {
  		if (errno != ENOENT)
  			err = got_error_from_errno2("unlink", ondisk_path);
  	} else {
  		size_t root_len = strlen(root_path);
  		err = got_path_dirname(&parent, ondisk_path);
  		if (err)
  			goto done;
  		while (got_path_cmp(parent, root_path,
  		    strlen(parent), root_len) != 0) {
  			free(ondisk_path);
  			ondisk_path = parent;
  			parent = NULL;
  			if (rmdir(ondisk_path) == -1) {
  				if (errno != ENOTEMPTY)
  					err = got_error_from_errno2("rmdir",
  					    ondisk_path);
  				break;
  			}
  			err = got_path_dirname(&parent, ondisk_path);
  			if (err)
  				break;
  		}
  	}
  done:
  	free(ondisk_path);
  	free(parent);
  	return err;
  }
  
  static const struct got_error *
  delete_blob(struct got_worktree *worktree, struct got_fileindex *fileindex,
      struct got_fileindex_entry *ie, struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	const struct got_error *err = NULL;
  	unsigned char status;
  	struct stat sb;
  	char *ondisk_path;
  
  	if (get_staged_status(ie) != GOT_STATUS_NO_CHANGE)
  		return got_error_path(ie->path, GOT_ERR_FILE_STAGED);
  
  	if (asprintf(&ondisk_path, "%s/%s", worktree->root_path, ie->path)
  	    == -1)
  		return got_error_from_errno("asprintf");
  
  	err = get_file_status(&status, &sb, ie, ondisk_path, -1, NULL, repo);
  	if (err)
  		goto done;
  
  	if (S_ISLNK(sb.st_mode) && status != GOT_STATUS_NO_CHANGE) {
  		char ondisk_target[PATH_MAX];
  		ssize_t ondisk_len = readlink(ondisk_path, ondisk_target,
  		    sizeof(ondisk_target));
  		if (ondisk_len == -1) {
  			err = got_error_from_errno2("readlink", ondisk_path);
  			goto done;
  		}
  		ondisk_target[ondisk_len] = '\0';
  		err = install_symlink_conflict(NULL, worktree->base_commit_id,
  		    NULL, NULL, /* XXX pass common ancestor info? */
  		    ondisk_target, ondisk_path);
  		if (err)
  			goto done;
  		err = (*progress_cb)(progress_arg, GOT_STATUS_CONFLICT,
  		    ie->path);
  		goto done;
  	}
  
  	if (status == GOT_STATUS_MODIFY || status == GOT_STATUS_CONFLICT ||
  	    status == GOT_STATUS_ADD) {
  		err = (*progress_cb)(progress_arg, GOT_STATUS_MERGE, ie->path);
  		if (err)
  			goto done;
  		/*
  		 * Preserve the working file and change the deleted blob's
  		 * entry into a schedule-add entry.
  		 */
  		err = got_fileindex_entry_update(ie, worktree->root_fd,
  		    ie->path, NULL, NULL, 0);
  	} else {
  		err = (*progress_cb)(progress_arg, GOT_STATUS_DELETE, ie->path);
  		if (err)
  			goto done;
  		if (status == GOT_STATUS_NO_CHANGE) {
  			err = remove_ondisk_file(worktree->root_path, ie->path);
  			if (err)
  				goto done;
  		}
  		got_fileindex_entry_remove(fileindex, ie);
  	}
  done:
  	free(ondisk_path);
  	return err;
  }
  
  struct diff_cb_arg {
      struct got_fileindex *fileindex;
      struct got_worktree *worktree;
      struct got_repository *repo;
      got_worktree_checkout_cb progress_cb;
      void *progress_arg;
      got_cancel_cb cancel_cb;
      void *cancel_arg;
  };
  
  static const struct got_error *
  diff_old_new(void *arg, struct got_fileindex_entry *ie,
      struct got_tree_entry *te, const char *parent_path)
  {
  	struct diff_cb_arg *a = arg;
  
  	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
  		return got_error(GOT_ERR_CANCELLED);
  
  	return update_blob(a->worktree, a->fileindex, ie, te,
  	    ie->path, a->repo, a->progress_cb, a->progress_arg);
  }
  
  static const struct got_error *
  diff_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
  {
  	struct diff_cb_arg *a = arg;
  
  	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
  		return got_error(GOT_ERR_CANCELLED);
  
  	return delete_blob(a->worktree, a->fileindex, ie,
  	    a->repo, a->progress_cb, a->progress_arg);
  }
  
  static const struct got_error *
  diff_new(void *arg, struct got_tree_entry *te, const char *parent_path)
  {
  	struct diff_cb_arg *a = arg;
  	const struct got_error *err;
  	char *path;
  
  	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
  		return got_error(GOT_ERR_CANCELLED);
  
  	if (got_object_tree_entry_is_submodule(te))
  		return NULL;
  
  	if (asprintf(&path, "%s%s%s", parent_path,
  	    parent_path[0] ? "/" : "", te->name)
  	    == -1)
  		return got_error_from_errno("asprintf");
  
  	if (S_ISDIR(te->mode))
  		err = add_dir_on_disk(a->worktree, path);
  	else
  		err = update_blob(a->worktree, a->fileindex, NULL, te, path,
  		    a->repo, a->progress_cb, a->progress_arg);
  
  	free(path);
  	return err;
  }
  
  const struct got_error *
  got_worktree_get_uuid(char **uuidstr, struct got_worktree *worktree)
  {
  	uint32_t uuid_status;
  
  	uuid_to_string(&worktree->uuid, uuidstr, &uuid_status);
  	if (uuid_status != uuid_s_ok) {
  		*uuidstr = NULL;
  		return got_error_uuid(uuid_status, "uuid_to_string");
  	}
  
  	return NULL;
  }
  
  static const struct got_error *
  get_ref_name(char **refname, struct got_worktree *worktree, const char *prefix)
  {
  	const struct got_error *err = NULL;
  	char *uuidstr = NULL;
  
  	*refname = NULL;
  
  	err = got_worktree_get_uuid(&uuidstr, worktree);
  	if (err)
  		return err;
  
  	if (asprintf(refname, "%s-%s", prefix, uuidstr) == -1) {
  		err = got_error_from_errno("asprintf");
  		*refname = NULL;
  	}
  	free(uuidstr);
  	return err;
  }
  
  const struct got_error *
  got_worktree_get_base_ref_name(char **refname, struct got_worktree *worktree)
  {
  	return get_ref_name(refname, worktree, GOT_WORKTREE_BASE_REF_PREFIX);
  }
  
  static const struct got_error *
  get_rebase_tmp_ref_name(char **refname, struct got_worktree *worktree)
  {
  	return get_ref_name(refname, worktree,
  	    GOT_WORKTREE_REBASE_TMP_REF_PREFIX);
  }
  
  static const struct got_error *
  get_newbase_symref_name(char **refname, struct got_worktree *worktree)
  {
  	return get_ref_name(refname, worktree, GOT_WORKTREE_NEWBASE_REF_PREFIX);
  }
  
  static const struct got_error *
  get_rebase_branch_symref_name(char **refname, struct got_worktree *worktree)
  {
  	return get_ref_name(refname, worktree,
  	    GOT_WORKTREE_REBASE_BRANCH_REF_PREFIX);
  }
  
  static const struct got_error *
  get_rebase_commit_ref_name(char **refname, struct got_worktree *worktree)
  {
  	return get_ref_name(refname, worktree,
  	    GOT_WORKTREE_REBASE_COMMIT_REF_PREFIX);
  }
  
  static const struct got_error *
  get_histedit_tmp_ref_name(char **refname, struct got_worktree *worktree)
  {
  	return get_ref_name(refname, worktree,
  	    GOT_WORKTREE_HISTEDIT_TMP_REF_PREFIX);
  }
  
  static const struct got_error *
  get_histedit_branch_symref_name(char **refname, struct got_worktree *worktree)
  {
  	return get_ref_name(refname, worktree,
  	    GOT_WORKTREE_HISTEDIT_BRANCH_REF_PREFIX);
  }
  
  static const struct got_error *
  get_histedit_base_commit_ref_name(char **refname, struct got_worktree *worktree)
  {
  	return get_ref_name(refname, worktree,
  	    GOT_WORKTREE_HISTEDIT_BASE_COMMIT_REF_PREFIX);
  }
  
  static const struct got_error *
  get_histedit_commit_ref_name(char **refname, struct got_worktree *worktree)
  {
  	return get_ref_name(refname, worktree,
  	    GOT_WORKTREE_HISTEDIT_COMMIT_REF_PREFIX);
  }
  
  const struct got_error *
  got_worktree_get_histedit_script_path(char **path,
      struct got_worktree *worktree)
  {
  	if (asprintf(path, "%s/%s/%s", worktree->root_path,
  	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_HISTEDIT_SCRIPT) == -1) {
  		*path = NULL;
  		return got_error_from_errno("asprintf");
  	}
  	return NULL;
  }
  
  static const struct got_error *
  get_merge_branch_ref_name(char **refname, struct got_worktree *worktree)
  {
  	return get_ref_name(refname, worktree,
  	    GOT_WORKTREE_MERGE_BRANCH_REF_PREFIX);
  }
  
  static const struct got_error *
  get_merge_commit_ref_name(char **refname, struct got_worktree *worktree)
  {
  	return get_ref_name(refname, worktree,
  	    GOT_WORKTREE_MERGE_COMMIT_REF_PREFIX);
  }
  
  /*
   * Prevent Git's garbage collector from deleting our base commit by
   * setting a reference to our base commit's ID.
   */
  static const struct got_error *
  ref_base_commit(struct got_worktree *worktree, struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	struct got_reference *ref = NULL;
  	char *refname;
  
  	err = got_worktree_get_base_ref_name(&refname, worktree);
  	if (err)
  		return err;
  
  	err = got_ref_alloc(&ref, refname, worktree->base_commit_id);
  	if (err)
  		goto done;
  
  	err = got_ref_write(ref, repo);
  done:
  	free(refname);
  	if (ref)
  		got_ref_close(ref);
  	return err;
  }
  
  static const struct got_error *
  get_fileindex_path(char **fileindex_path, struct got_worktree *worktree)
  {
  	const struct got_error *err = NULL;
  
  	if (asprintf(fileindex_path, "%s/%s/%s", worktree->root_path,
  	    GOT_WORKTREE_GOT_DIR, GOT_WORKTREE_FILE_INDEX) == -1) {
  		err = got_error_from_errno("asprintf");
  		*fileindex_path = NULL;
  	}
  	return err;
  }
  
  
  static const struct got_error *
  open_fileindex(struct got_fileindex **fileindex, char **fileindex_path,
      struct got_worktree *worktree)
  {
  	const struct got_error *err = NULL;
  	FILE *index = NULL;
  
  	*fileindex_path = NULL;
  	*fileindex = got_fileindex_alloc();
  	if (*fileindex == NULL)
  		return got_error_from_errno("got_fileindex_alloc");
  
  	err = get_fileindex_path(fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	index = fopen(*fileindex_path, "rbe");
  	if (index == NULL) {
  		if (errno != ENOENT)
  			err = got_error_from_errno2("fopen", *fileindex_path);
  	} else {
  		err = got_fileindex_read(*fileindex, index);
  		if (fclose(index) == EOF && err == NULL)
  			err = got_error_from_errno("fclose");
  	}
  done:
  	if (err) {
  		free(*fileindex_path);
  		*fileindex_path = NULL;
  		got_fileindex_free(*fileindex);
  		*fileindex = NULL;
  	}
  	return err;
  }
  
  struct bump_base_commit_id_arg {
  	struct got_object_id *base_commit_id;
  	const char *path;
  	size_t path_len;
  	const char *entry_name;
  	got_worktree_checkout_cb progress_cb;
  	void *progress_arg;
  };
  
  /* Bump base commit ID of all files within an updated part of the work tree. */
  static const struct got_error *
  bump_base_commit_id(void *arg, struct got_fileindex_entry *ie)
  {
  	const struct got_error *err;
  	struct bump_base_commit_id_arg *a = arg;
  
  	if (a->entry_name) {
  		if (strcmp(ie->path, a->path) != 0)
  			return NULL;
  	} else if (!got_path_is_child(ie->path, a->path, a->path_len))
  		return NULL;
  
  	if (got_fileindex_entry_was_skipped(ie))
  		return NULL;
  
  	if (memcmp(ie->commit_sha1, a->base_commit_id->sha1,
  	    SHA1_DIGEST_LENGTH) == 0)
  		return NULL;
  
  	if (a->progress_cb) {
  		err = (*a->progress_cb)(a->progress_arg, GOT_STATUS_BUMP_BASE,
  		    ie->path);
  		if (err)
  			return err;
  	}
  	memcpy(ie->commit_sha1, a->base_commit_id->sha1, SHA1_DIGEST_LENGTH);
  	return NULL;
  }
  
  static const struct got_error *
  bump_base_commit_id_everywhere(struct got_worktree *worktree,
      struct got_fileindex *fileindex,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	struct bump_base_commit_id_arg bbc_arg;
  
  	bbc_arg.base_commit_id = worktree->base_commit_id;
  	bbc_arg.entry_name = NULL;
  	bbc_arg.path = "";
  	bbc_arg.path_len = 0;
  	bbc_arg.progress_cb = progress_cb;
  	bbc_arg.progress_arg = progress_arg;
  
  	return got_fileindex_for_each_entry_safe(fileindex,
  	    bump_base_commit_id, &bbc_arg);
  }
  
  static const struct got_error *
  sync_fileindex(struct got_fileindex *fileindex, const char *fileindex_path)
  {
  	const struct got_error *err = NULL;
  	char *new_fileindex_path = NULL;
  	FILE *new_index = NULL;
  	struct timespec timeout;
  
  	err = got_opentemp_named(&new_fileindex_path, &new_index,
  	    fileindex_path);
  	if (err)
  		goto done;
  
  	err = got_fileindex_write(fileindex, new_index);
  	if (err)
  		goto done;
  
  	if (rename(new_fileindex_path, fileindex_path) != 0) {
  		err = got_error_from_errno3("rename", new_fileindex_path,
  		    fileindex_path);
  		unlink(new_fileindex_path);
  	}
  
  	/*
  	 * Sleep for a short amount of time to ensure that files modified after
  	 * this program exits have a different time stamp from the one which
  	 * was recorded in the file index.
  	 */
  	timeout.tv_sec = 0;
  	timeout.tv_nsec = 1;
  	nanosleep(&timeout,  NULL);
  done:
  	if (new_index)
  		fclose(new_index);
  	free(new_fileindex_path);
  	return err;
  }
  
  static const struct got_error *
  find_tree_entry_for_checkout(int *entry_type, char **tree_relpath,
      struct got_object_id **tree_id, const char *wt_relpath,
      struct got_commit_object *base_commit, struct got_worktree *worktree,
      struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	struct got_object_id *id = NULL;
  	char *in_repo_path = NULL;
  	int is_root_wt = got_path_is_root_dir(worktree->path_prefix);
  
  	*entry_type = GOT_OBJ_TYPE_ANY;
  	*tree_relpath = NULL;
  	*tree_id = NULL;
  
  	if (wt_relpath[0] == '\0') {
  		/* Check out all files within the work tree. */
  		*entry_type = GOT_OBJ_TYPE_TREE;
  		*tree_relpath = strdup("");
  		if (*tree_relpath == NULL) {
  			err = got_error_from_errno("strdup");
  			goto done;
  		}
  		err = got_object_id_by_path(tree_id, repo, base_commit,
  		    worktree->path_prefix);
  		if (err)
  			goto done;
  		return NULL;
  	}
  
  	/* Check out a subset of files in the work tree. */
  
  	if (asprintf(&in_repo_path, "%s%s%s", worktree->path_prefix,
  	    is_root_wt ? "" : "/", wt_relpath) == -1) {
  		err = got_error_from_errno("asprintf");
  		goto done;
  	}
  
  	err = got_object_id_by_path(&id, repo, base_commit, in_repo_path);
  	if (err)
  		goto done;
  
  	free(in_repo_path);
  	in_repo_path = NULL;
  
  	err = got_object_get_type(entry_type, repo, id);
  	if (err)
  		goto done;
  
  	if (*entry_type == GOT_OBJ_TYPE_BLOB) {
  		/* Check out a single file. */
  		if (strchr(wt_relpath, '/')  == NULL) {
  			/* Check out a single file in work tree's root dir. */
  			in_repo_path = strdup(worktree->path_prefix);
  			if (in_repo_path == NULL) {
  				err = got_error_from_errno("strdup");
  				goto done;
  			}
  			*tree_relpath = strdup("");
  			if (*tree_relpath == NULL) {
  				err = got_error_from_errno("strdup");
  				goto done;
  			}
  		} else {
  			/* Check out a single file in a subdirectory. */
  			err = got_path_dirname(tree_relpath, wt_relpath);
  			if (err)
  				return err;
  			if (asprintf(&in_repo_path, "%s%s%s",
  			    worktree->path_prefix, is_root_wt ? "" : "/",
  			    *tree_relpath) == -1) {
  				err = got_error_from_errno("asprintf");
  				goto done;
  			}
  		}
  		err = got_object_id_by_path(tree_id, repo,
  		    base_commit, in_repo_path);
  	} else {
  		/* Check out all files within a subdirectory. */
  		*tree_id = got_object_id_dup(id);
  		if (*tree_id == NULL) {
  			err = got_error_from_errno("got_object_id_dup");
  			goto done;
  		}
  		*tree_relpath = strdup(wt_relpath);
  		if (*tree_relpath == NULL) {
  			err = got_error_from_errno("strdup");
  			goto done;
  		}
  	}
  done:
  	free(id);
  	free(in_repo_path);
  	if (err) {
  		*entry_type = GOT_OBJ_TYPE_ANY;
  		free(*tree_relpath);
  		*tree_relpath = NULL;
  		free(*tree_id);
  		*tree_id = NULL;
  	}
  	return err;
  }
  
  static const struct got_error *
  checkout_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
      const char *relpath, struct got_object_id *tree_id, const char *entry_name,
      struct got_repository *repo, got_worktree_checkout_cb progress_cb,
      void *progress_arg, got_cancel_cb cancel_cb, void *cancel_arg)
  {
  	const struct got_error *err = NULL;
  	struct got_commit_object *commit = NULL;
  	struct got_tree_object *tree = NULL;
  	struct got_fileindex_diff_tree_cb diff_cb;
  	struct diff_cb_arg arg;
  
  	err = ref_base_commit(worktree, repo);
  	if (err) {
  		if (!(err->code == GOT_ERR_ERRNO &&
  		    (errno == EACCES || errno == EROFS)))
  			goto done;
  		err = (*progress_cb)(progress_arg,
  		    GOT_STATUS_BASE_REF_ERR, worktree->root_path);
  		if (err)
  			return err;
  	}
  
  	err = got_object_open_as_commit(&commit, repo,
  	    worktree->base_commit_id);
  	if (err)
  		goto done;
  
  	err = got_object_open_as_tree(&tree, repo, tree_id);
  	if (err)
  		goto done;
  
  	if (entry_name &&
  	    got_object_tree_find_entry(tree, entry_name) == NULL) {
  		err = got_error_path(entry_name, GOT_ERR_NO_TREE_ENTRY);
  		goto done;
  	}
  
  	diff_cb.diff_old_new = diff_old_new;
  	diff_cb.diff_old = diff_old;
  	diff_cb.diff_new = diff_new;
  	arg.fileindex = fileindex;
  	arg.worktree = worktree;
  	arg.repo = repo;
  	arg.progress_cb = progress_cb;
  	arg.progress_arg = progress_arg;
  	arg.cancel_cb = cancel_cb;
  	arg.cancel_arg = cancel_arg;
  	err = got_fileindex_diff_tree(fileindex, tree, relpath,
  	    entry_name, repo, &diff_cb, &arg);
  done:
  	if (tree)
  		got_object_tree_close(tree);
  	if (commit)
  		got_object_commit_close(commit);
  	return err;
  }
  
  const struct got_error *
  got_worktree_checkout_files(struct got_worktree *worktree,
      struct got_pathlist_head *paths, struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg,
      got_cancel_cb cancel_cb, void *cancel_arg)
  {
  	const struct got_error *err = NULL, *sync_err, *unlockerr;
  	struct got_commit_object *commit = NULL;
  	struct got_tree_object *tree = NULL;
  	struct got_fileindex *fileindex = NULL;
  	char *fileindex_path = NULL;
  	struct got_pathlist_entry *pe;
  	struct tree_path_data {
  		STAILQ_ENTRY(tree_path_data) entry;
  		struct got_object_id *tree_id;
  		int entry_type;
  		char *relpath;
  		char *entry_name;
  	} *tpd = NULL;
  	STAILQ_HEAD(tree_paths, tree_path_data) tree_paths;
  
  	STAILQ_INIT(&tree_paths);
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = got_object_open_as_commit(&commit, repo,
  	    worktree->base_commit_id);
  	if (err)
  		goto done;
  
  	/* Map all specified paths to in-repository trees. */
  	TAILQ_FOREACH(pe, paths, entry) {
  		tpd = malloc(sizeof(*tpd));
  		if (tpd == NULL) {
  			err = got_error_from_errno("malloc");
  			goto done;
  		}
  
  		err = find_tree_entry_for_checkout(&tpd->entry_type,
  		    &tpd->relpath, &tpd->tree_id, pe->path, commit,
  		    worktree, repo);
  		if (err) {
  			free(tpd);
  			goto done;
  		}
  
  		if (tpd->entry_type == GOT_OBJ_TYPE_BLOB) {
  			err = got_path_basename(&tpd->entry_name, pe->path);
  			if (err) {
  				free(tpd->relpath);
  				free(tpd->tree_id);
  				free(tpd);
  				goto done;
  			}
  		} else
  			tpd->entry_name = NULL;
  
  		STAILQ_INSERT_TAIL(&tree_paths, tpd, entry);
  	}
  
  	/*
  	 * Read the file index.
  	 * Checking out files is supposed to be an idempotent operation.
  	 * If the on-disk file index is incomplete we will try to complete it.
  	 */
  	err = open_fileindex(&fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	tpd = STAILQ_FIRST(&tree_paths);
  	TAILQ_FOREACH(pe, paths, entry) {
  		struct bump_base_commit_id_arg bbc_arg;
  
  		err = checkout_files(worktree, fileindex, tpd->relpath,
  		    tpd->tree_id, tpd->entry_name, repo,
  		    progress_cb, progress_arg, cancel_cb, cancel_arg);
  		if (err)
  			break;
  
  		bbc_arg.base_commit_id = worktree->base_commit_id;
  		bbc_arg.entry_name = tpd->entry_name;
  		bbc_arg.path = pe->path;
  		bbc_arg.path_len = pe->path_len;
  		bbc_arg.progress_cb = progress_cb;
  		bbc_arg.progress_arg = progress_arg;
  		err = got_fileindex_for_each_entry_safe(fileindex,
  		    bump_base_commit_id, &bbc_arg);
  		if (err)
  			break;
  
  		tpd = STAILQ_NEXT(tpd, entry);
  	}
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	free(fileindex_path);
  	if (tree)
  		got_object_tree_close(tree);
  	if (commit)
  		got_object_commit_close(commit);
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	while (!STAILQ_EMPTY(&tree_paths)) {
  		tpd = STAILQ_FIRST(&tree_paths);
  		STAILQ_REMOVE_HEAD(&tree_paths, entry);
  		free(tpd->relpath);
  		free(tpd->tree_id);
  		free(tpd);
  	}
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  struct merge_file_cb_arg {
      struct got_worktree *worktree;
      struct got_fileindex *fileindex;
      got_worktree_checkout_cb progress_cb;
      void *progress_arg;
      got_cancel_cb cancel_cb;
      void *cancel_arg;
      const char *label_orig;
      struct got_object_id *commit_id2;
      int allow_bad_symlinks;
  };
  
  static const struct got_error *
  merge_file_cb(void *arg, struct got_blob_object *blob1,
      struct got_blob_object *blob2, FILE *f1, FILE *f2,
      struct got_object_id *id1, struct got_object_id *id2,
      const char *path1, const char *path2,
      mode_t mode1, mode_t mode2, struct got_repository *repo)
  {
  	static const struct got_error *err = NULL;
  	struct merge_file_cb_arg *a = arg;
  	struct got_fileindex_entry *ie;
  	char *ondisk_path = NULL;
  	struct stat sb;
  	unsigned char status;
  	int local_changes_subsumed;
  	FILE *f_orig = NULL, *f_deriv = NULL, *f_deriv2 = NULL;
  	char *id_str = NULL, *label_deriv2 = NULL;
  
  	if (blob1 && blob2) {
  		ie = got_fileindex_entry_get(a->fileindex, path2,
  		    strlen(path2));
  		if (ie == NULL)
  			return (*a->progress_cb)(a->progress_arg,
  			    GOT_STATUS_MISSING, path2);
  
  		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
  		    path2) == -1)
  			return got_error_from_errno("asprintf");
  
  		err = get_file_status(&status, &sb, ie, ondisk_path, -1, NULL,
  		    repo);
  		if (err)
  			goto done;
  
  		if (status == GOT_STATUS_DELETE) {
  			err = (*a->progress_cb)(a->progress_arg,
  			    GOT_STATUS_MERGE, path2);
  			goto done;
  		}
  		if (status != GOT_STATUS_NO_CHANGE &&
  		    status != GOT_STATUS_MODIFY &&
  		    status != GOT_STATUS_CONFLICT &&
  		    status != GOT_STATUS_ADD) {
  			err = (*a->progress_cb)(a->progress_arg, status, path2);
  			goto done;
  		}
  
  		if (S_ISLNK(mode1) && S_ISLNK(mode2)) {
  			char *link_target2;
  			err = got_object_blob_read_to_str(&link_target2, blob2);
  			if (err)
  				goto done;
  			err = merge_symlink(a->worktree, blob1, ondisk_path,
  			    path2, a->label_orig, link_target2, a->commit_id2,
  			    repo, a->progress_cb, a->progress_arg);
  			free(link_target2);
  		} else {
  			int fd;
  
  			f_orig = got_opentemp();
  			if (f_orig == NULL) {
  				err = got_error_from_errno("got_opentemp");
  				goto done;
  			}
  			err = got_object_blob_dump_to_file(NULL, NULL, NULL,
  			    f_orig, blob1);
  			if (err)
  				goto done;
  
  			f_deriv2 = got_opentemp();
  			if (f_deriv2 == NULL)
  				goto done;
  			err = got_object_blob_dump_to_file(NULL, NULL, NULL,
  			    f_deriv2, blob2);
  			if (err)
  				goto done;
  
  			fd = open(ondisk_path,
  			    O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
  			if (fd == -1) {
  				err = got_error_from_errno2("open",
  				    ondisk_path);
  				goto done;
  			}
  			f_deriv = fdopen(fd, "r");
  			if (f_deriv == NULL) {
  				err = got_error_from_errno2("fdopen",
  				    ondisk_path);
  				close(fd);
  				goto done;
  			}
  			err = got_object_id_str(&id_str, a->commit_id2);
  			if (err)
  				goto done;
  			if (asprintf(&label_deriv2, "%s: commit %s",
  			    GOT_MERGE_LABEL_MERGED, id_str) == -1) {
  				err = got_error_from_errno("asprintf");
  				goto done;
  			}
  			err = merge_file(&local_changes_subsumed, a->worktree,
  			    f_orig, f_deriv, f_deriv2, ondisk_path, path2,
  			    sb.st_mode, a->label_orig, NULL, label_deriv2,
  			    GOT_DIFF_ALGORITHM_PATIENCE, repo,
  			    a->progress_cb, a->progress_arg);
  		}
  	} else if (blob1) {
  		ie = got_fileindex_entry_get(a->fileindex, path1,
  		    strlen(path1));
  		if (ie == NULL)
  			return (*a->progress_cb)(a->progress_arg,
  			    GOT_STATUS_MISSING, path1);
  
  		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
  		    path1) == -1)
  			return got_error_from_errno("asprintf");
  
  		err = get_file_status(&status, &sb, ie, ondisk_path, -1, NULL,
  		    repo);
  		if (err)
  			goto done;
  
  		switch (status) {
  		case GOT_STATUS_NO_CHANGE:
  			err = (*a->progress_cb)(a->progress_arg,
  			    GOT_STATUS_DELETE, path1);
  			if (err)
  				goto done;
  			err = remove_ondisk_file(a->worktree->root_path, path1);
  			if (err)
  				goto done;
  			if (ie)
  				got_fileindex_entry_mark_deleted_from_disk(ie);
  			break;
  		case GOT_STATUS_DELETE:
  		case GOT_STATUS_MISSING:
  			err = (*a->progress_cb)(a->progress_arg,
  			    GOT_STATUS_DELETE, path1);
  			if (err)
  				goto done;
  			if (ie)
  				got_fileindex_entry_mark_deleted_from_disk(ie);
  			break;
  		case GOT_STATUS_ADD: {
  			struct got_object_id *id;
  			FILE *blob1_f;
  			off_t blob1_size;
  			/*
  			 * Delete the added file only if its content already
  			 * exists in the repository.
  			 */
  			err = got_object_blob_file_create(&id, &blob1_f,
  			    &blob1_size, path1);
  			if (err)
  				goto done;
  			if (got_object_id_cmp(id, id1) == 0) {
  				err = (*a->progress_cb)(a->progress_arg,
  				    GOT_STATUS_DELETE, path1);
  				if (err)
  					goto done;
  				err = remove_ondisk_file(a->worktree->root_path,
  				    path1);
  				if (err)
  					goto done;
  				if (ie)
  					got_fileindex_entry_remove(a->fileindex,
  					    ie);
  			} else {
  				err = (*a->progress_cb)(a->progress_arg,
  				    GOT_STATUS_CANNOT_DELETE, path1);
  			}
  			if (fclose(blob1_f) == EOF && err == NULL)
  				err = got_error_from_errno("fclose");
  			free(id);
  			if (err)
  				goto done;
  			break;
  		}
  		case GOT_STATUS_MODIFY:
  		case GOT_STATUS_CONFLICT:
  			err = (*a->progress_cb)(a->progress_arg,
  			    GOT_STATUS_CANNOT_DELETE, path1);
  			if (err)
  				goto done;
  			break;
  		case GOT_STATUS_OBSTRUCTED:
  			err = (*a->progress_cb)(a->progress_arg, status, path1);
  			if (err)
  				goto done;
  			break;
  		default:
  			break;
  		}
  	} else if (blob2) {
  		if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
  		    path2) == -1)
  			return got_error_from_errno("asprintf");
  		ie = got_fileindex_entry_get(a->fileindex, path2,
  		    strlen(path2));
  		if (ie) {
  			err = get_file_status(&status, &sb, ie, ondisk_path,
  			    -1, NULL, repo);
  			if (err)
  				goto done;
  			if (status != GOT_STATUS_NO_CHANGE &&
  			    status != GOT_STATUS_MODIFY &&
  			    status != GOT_STATUS_CONFLICT &&
  			    status != GOT_STATUS_ADD) {
  				err = (*a->progress_cb)(a->progress_arg,
  				    status, path2);
  				goto done;
  			}
  			if (S_ISLNK(mode2) && S_ISLNK(sb.st_mode)) {
  				char *link_target2;
  				err = got_object_blob_read_to_str(&link_target2,
  				    blob2);
  				if (err)
  					goto done;
  				err = merge_symlink(a->worktree, NULL,
  				    ondisk_path, path2, a->label_orig,
  				    link_target2, a->commit_id2, repo,
  				    a->progress_cb, a->progress_arg);
  				free(link_target2);
  			} else if (S_ISREG(sb.st_mode)) {
  				err = merge_blob(&local_changes_subsumed,
  				    a->worktree, NULL, ondisk_path, path2,
  				    sb.st_mode, a->label_orig, blob2,
  				    a->commit_id2, repo, a->progress_cb,
  				    a->progress_arg);
  			} else {
  				err = got_error_path(ondisk_path,
  				    GOT_ERR_FILE_OBSTRUCTED);
  			}
  			if (err)
  				goto done;
  			if (status == GOT_STATUS_DELETE) {
  				err = got_fileindex_entry_update(ie,
  				    a->worktree->root_fd, path2, blob2->id.sha1,
  				    a->worktree->base_commit_id->sha1, 0);
  				if (err)
  					goto done;
  			}
  		} else {
  			int is_bad_symlink = 0;
  			sb.st_mode = GOT_DEFAULT_FILE_MODE;
  			if (S_ISLNK(mode2)) {
  				err = install_symlink(&is_bad_symlink,
  				    a->worktree, ondisk_path, path2, blob2, 0,
  				    0, 1, a->allow_bad_symlinks, repo,
  				    a->progress_cb, a->progress_arg);
  			} else {
  				err = install_blob(a->worktree, ondisk_path, path2,
  				    mode2, sb.st_mode, blob2, 0, 0, 0, 1, repo,
  				    a->progress_cb, a->progress_arg);
  			}
  			if (err)
  				goto done;
  			err = got_fileindex_entry_alloc(&ie, path2);
  			if (err)
  				goto done;
  			err = got_fileindex_entry_update(ie,
  			    a->worktree->root_fd, path2, NULL, NULL, 1);
  			if (err) {
  				got_fileindex_entry_free(ie);
  				goto done;
  			}
  			err = got_fileindex_entry_add(a->fileindex, ie);
  			if (err) {
  				got_fileindex_entry_free(ie);
  				goto done;
  			}
  			if (is_bad_symlink) {
  				got_fileindex_entry_filetype_set(ie,
  				    GOT_FILEIDX_MODE_BAD_SYMLINK);
  			}
  		}
  	}
  done:
  	if (f_orig && fclose(f_orig) == EOF && err == NULL)
  		err = got_error_from_errno("fclose");
  	if (f_deriv && fclose(f_deriv) == EOF && err == NULL)
  		err = got_error_from_errno("fclose");
  	if (f_deriv2 && fclose(f_deriv2) == EOF && err == NULL)
  		err = got_error_from_errno("fclose");
  	free(id_str);
  	free(label_deriv2);
  	free(ondisk_path);
  	return err;
  }
  
  static const struct got_error *
  check_mixed_commits(void *arg, struct got_fileindex_entry *ie)
  {
  	struct got_worktree *worktree = arg;
  
  	/* Reject merges into a work tree with mixed base commits. */
  	if (got_fileindex_entry_has_commit(ie) &&
  	    memcmp(ie->commit_sha1, worktree->base_commit_id->sha1,
  	    SHA1_DIGEST_LENGTH) != 0)
  		return got_error(GOT_ERR_MIXED_COMMITS);
  
  	return NULL;
  }
  
  struct check_merge_conflicts_arg {
  	struct got_worktree *worktree;
  	struct got_fileindex *fileindex;
  	struct got_repository *repo;
  };
  
  static const struct got_error *
  check_merge_conflicts(void *arg, struct got_blob_object *blob1,
      struct got_blob_object *blob2, FILE *f1, FILE *f2,
      struct got_object_id *id1, struct got_object_id *id2,
      const char *path1, const char *path2,
      mode_t mode1, mode_t mode2, struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	struct check_merge_conflicts_arg *a = arg;
  	unsigned char status;
  	struct stat sb;
  	struct got_fileindex_entry *ie;
  	const char *path = path2 ? path2 : path1;
  	struct got_object_id *id = id2 ? id2 : id1;
  	char *ondisk_path;
  
  	if (id == NULL)
  		return NULL;
  
  	ie = got_fileindex_entry_get(a->fileindex, path, strlen(path));
  	if (ie == NULL)
  		return NULL;
  
  	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
  	    == -1)
  		return got_error_from_errno("asprintf");
  
  	/* Reject merges into a work tree with conflicted files. */
  	err = get_file_status(&status, &sb, ie, ondisk_path, -1, NULL, a->repo);
  	free(ondisk_path);
  	if (err)
  		return err;
  	if (status == GOT_STATUS_CONFLICT)
  		return got_error(GOT_ERR_CONFLICTS);
  
  	return NULL;
  }
  
  static const struct got_error *
  merge_files(struct got_worktree *worktree, struct got_fileindex *fileindex,
      const char *fileindex_path, struct got_object_id *commit_id1,
      struct got_object_id *commit_id2, struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg,
      got_cancel_cb cancel_cb, void *cancel_arg)
  {
  	const struct got_error *err = NULL, *sync_err;
  	struct got_object_id *tree_id1 = NULL, *tree_id2 = NULL;
  	struct got_tree_object *tree1 = NULL, *tree2 = NULL;
  	struct got_commit_object *commit1 = NULL, *commit2 = NULL;
  	struct check_merge_conflicts_arg cmc_arg;
  	struct merge_file_cb_arg arg;
  	char *label_orig = NULL;
  	FILE *f1 = NULL, *f2 = NULL;
  
  	if (commit_id1) {
  		err = got_object_open_as_commit(&commit1, repo, commit_id1);
  		if (err)
  			goto done;
  		err = got_object_id_by_path(&tree_id1, repo, commit1,
  		    worktree->path_prefix);
  		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
  			goto done;
  	}
  	if (tree_id1) {
  		char *id_str;
  
  		err = got_object_open_as_tree(&tree1, repo, tree_id1);
  		if (err)
  			goto done;
  
  		err = got_object_id_str(&id_str, commit_id1);
  		if (err)
  			goto done;
  
  		if (asprintf(&label_orig, "%s: commit %s",
  		    GOT_MERGE_LABEL_BASE, id_str) == -1) {
  			err = got_error_from_errno("asprintf");
  			free(id_str);
  			goto done;
  		}
  		free(id_str);
  
  		f1 = got_opentemp();
  		if (f1 == NULL) {
  			err = got_error_from_errno("got_opentemp");
  			goto done;
  		}
  	}
  
  	err = got_object_open_as_commit(&commit2, repo, commit_id2);
  	if (err)
  		goto done;
  
  	err = got_object_id_by_path(&tree_id2, repo, commit2,
  	    worktree->path_prefix);
  	if (err)
  		goto done;
  
  	err = got_object_open_as_tree(&tree2, repo, tree_id2);
  	if (err)
  		goto done;
  
  	f2 = got_opentemp();
  	if (f2 == NULL) {
  		err = got_error_from_errno("got_opentemp");
  		goto done;
  	}
  
  	cmc_arg.worktree = worktree;
  	cmc_arg.fileindex = fileindex;
  	cmc_arg.repo = repo;
  	err = got_diff_tree(tree1, tree2, f1, f2, "", "", repo,
  	    check_merge_conflicts, &cmc_arg, 0);
  	if (err)
  		goto done;
  
  	arg.worktree = worktree;
  	arg.fileindex = fileindex;
  	arg.progress_cb = progress_cb;
  	arg.progress_arg = progress_arg;
  	arg.cancel_cb = cancel_cb;
  	arg.cancel_arg = cancel_arg;
  	arg.label_orig = label_orig;
  	arg.commit_id2 = commit_id2;
  	arg.allow_bad_symlinks = 1; /* preserve bad symlinks across merges */
  	err = got_diff_tree(tree1, tree2, f1, f2, "", "", repo,
  	    merge_file_cb, &arg, 1);
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	if (commit1)
  		got_object_commit_close(commit1);
  	if (commit2)
  		got_object_commit_close(commit2);
  	if (tree1)
  		got_object_tree_close(tree1);
  	if (tree2)
  		got_object_tree_close(tree2);
  	if (f1 && fclose(f1) == EOF && err == NULL)
  		err = got_error_from_errno("fclose");
  	if (f2 && fclose(f2) == EOF && err == NULL)
  		err = got_error_from_errno("fclose");
  	free(label_orig);
  	return err;
  }
  
  const struct got_error *
  got_worktree_merge_files(struct got_worktree *worktree,
      struct got_object_id *commit_id1, struct got_object_id *commit_id2,
      struct got_repository *repo, got_worktree_checkout_cb progress_cb,
      void *progress_arg, got_cancel_cb cancel_cb, void *cancel_arg)
  {
  	const struct got_error *err, *unlockerr;
  	char *fileindex_path = NULL;
  	struct got_fileindex *fileindex = NULL;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = open_fileindex(&fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	err = got_fileindex_for_each_entry_safe(fileindex, check_mixed_commits,
  	    worktree);
  	if (err)
  		goto done;
  
  	err = merge_files(worktree, fileindex, fileindex_path, commit_id1,
  	    commit_id2, repo, progress_cb, progress_arg,
  	    cancel_cb, cancel_arg);
  done:
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	free(fileindex_path);
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  struct diff_dir_cb_arg {
      struct got_fileindex *fileindex;
      struct got_worktree *worktree;
      const char *status_path;
      size_t status_path_len;
      struct got_repository *repo;
      got_worktree_status_cb status_cb;
      void *status_arg;
      got_cancel_cb cancel_cb;
      void *cancel_arg;
      /* A pathlist containing per-directory pathlists of ignore patterns. */
      struct got_pathlist_head *ignores;
      int report_unchanged;
      int no_ignores;
  };
  
  static const struct got_error *
  report_file_status(struct got_fileindex_entry *ie, const char *abspath,
      int dirfd, const char *de_name,
      got_worktree_status_cb status_cb, void *status_arg,
      struct got_repository *repo, int report_unchanged)
  {
  	const struct got_error *err = NULL;
  	unsigned char status = GOT_STATUS_NO_CHANGE;
  	unsigned char staged_status = get_staged_status(ie);
  	struct stat sb;
  	struct got_object_id blob_id, commit_id, staged_blob_id;
  	struct got_object_id *blob_idp = NULL, *commit_idp = NULL;
  	struct got_object_id *staged_blob_idp = NULL;
  
  	err = get_file_status(&status, &sb, ie, abspath, dirfd, de_name, repo);
  	if (err)
  		return err;
  
  	if (status == GOT_STATUS_NO_CHANGE &&
  	    staged_status == GOT_STATUS_NO_CHANGE && !report_unchanged)
  		return NULL;
  
  	if (got_fileindex_entry_has_blob(ie)) {
  		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
  		blob_idp = &blob_id;
  	}
  	if (got_fileindex_entry_has_commit(ie)) {
  		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
  		commit_idp = &commit_id;
  	}
  	if (staged_status == GOT_STATUS_ADD ||
  	    staged_status == GOT_STATUS_MODIFY) {
  		memcpy(staged_blob_id.sha1, ie->staged_blob_sha1,
  		    SHA1_DIGEST_LENGTH);
  		staged_blob_idp = &staged_blob_id;
  	}
  
  	return (*status_cb)(status_arg, status, staged_status,
  	    ie->path, blob_idp, staged_blob_idp, commit_idp, dirfd, de_name);
  }
  
  static const struct got_error *
  status_old_new(void *arg, struct got_fileindex_entry *ie,
      struct dirent *de, const char *parent_path, int dirfd)
  {
  	const struct got_error *err = NULL;
  	struct diff_dir_cb_arg *a = arg;
  	char *abspath;
  
  	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
  		return got_error(GOT_ERR_CANCELLED);
  
  	if (got_path_cmp(parent_path, a->status_path,
  	    strlen(parent_path), a->status_path_len) != 0 &&
  	    !got_path_is_child(parent_path, a->status_path, a->status_path_len))
  		return NULL;
  
  	if (parent_path[0]) {
  		if (asprintf(&abspath, "%s/%s/%s", a->worktree->root_path,
  		    parent_path, de->d_name) == -1)
  			return got_error_from_errno("asprintf");
  	} else {
  		if (asprintf(&abspath, "%s/%s", a->worktree->root_path,
  		    de->d_name) == -1)
  			return got_error_from_errno("asprintf");
  	}
  
  	err = report_file_status(ie, abspath, dirfd, de->d_name,
  	    a->status_cb, a->status_arg, a->repo, a->report_unchanged);
  	free(abspath);
  	return err;
  }
  
  static const struct got_error *
  status_old(void *arg, struct got_fileindex_entry *ie, const char *parent_path)
  {
  	struct diff_dir_cb_arg *a = arg;
  	struct got_object_id blob_id, commit_id;
  	unsigned char status;
  
  	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
  		return got_error(GOT_ERR_CANCELLED);
  
  	if (!got_path_is_child(ie->path, a->status_path, a->status_path_len))
  		return NULL;
  
  	memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
  	memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
  	if (got_fileindex_entry_has_file_on_disk(ie))
  		status = GOT_STATUS_MISSING;
  	else
  		status = GOT_STATUS_DELETE;
  	return (*a->status_cb)(a->status_arg, status, get_staged_status(ie),
  	    ie->path, &blob_id, NULL, &commit_id, -1, NULL);
  }
  
  void
  free_ignorelist(struct got_pathlist_head *ignorelist)
  {
  	struct got_pathlist_entry *pe;
  
  	TAILQ_FOREACH(pe, ignorelist, entry)
  		free((char *)pe->path);
  	got_pathlist_free(ignorelist);
  }
  
  void
  free_ignores(struct got_pathlist_head *ignores)
  {
  	struct got_pathlist_entry *pe;
  
  	TAILQ_FOREACH(pe, ignores, entry) {
  		struct got_pathlist_head *ignorelist = pe->data;
  		free_ignorelist(ignorelist);
  		free((char *)pe->path);
  	}
  	got_pathlist_free(ignores);
  }
  
  static const struct got_error *
  read_ignores(struct got_pathlist_head *ignores, const char *path, FILE *f)
  {
  	const struct got_error *err = NULL;
  	struct got_pathlist_entry *pe = NULL;
  	struct got_pathlist_head *ignorelist;
  	char *line = NULL, *pattern, *dirpath = NULL;
  	size_t linesize = 0;
  	ssize_t linelen;
  
  	ignorelist = calloc(1, sizeof(*ignorelist));
  	if (ignorelist == NULL)
  		return got_error_from_errno("calloc");
  	TAILQ_INIT(ignorelist);
  
  	while ((linelen = getline(&line, &linesize, f)) != -1) {
  		if (linelen > 0 && line[linelen - 1] == '\n')
  			line[linelen - 1] = '\0';
  
  		/* Git's ignores may contain comments. */
  		if (line[0] == '#')
  			continue;
  
  		/* Git's negated patterns are not (yet?) supported. */
  		if (line[0] == '!')
  			continue;
  
  		if (asprintf(&pattern, "%s%s%s", path, path[0] ? "/" : "",
  		    line) == -1) {
  			err = got_error_from_errno("asprintf");
  			goto done;
  		}
  		err = got_pathlist_insert(NULL, ignorelist, pattern, NULL);
  		if (err)
  			goto done;
  	}
  	if (ferror(f)) {
  		err = got_error_from_errno("getline");
  		goto done;
  	}
  
  	dirpath = strdup(path);
  	if (dirpath == NULL) {
  		err = got_error_from_errno("strdup");
  		goto done;
  	}
  	err = got_pathlist_insert(&pe, ignores, dirpath, ignorelist);
  done:
  	free(line);
  	if (err || pe == NULL) {
  		free(dirpath);
  		free_ignorelist(ignorelist);
  	}
  	return err;
  }
  
  int
  match_ignores(struct got_pathlist_head *ignores, const char *path)
  {
  	struct got_pathlist_entry *pe;
  
  	/* Handle patterns which match in all directories. */
  	TAILQ_FOREACH(pe, ignores, entry) {
  		struct got_pathlist_head *ignorelist = pe->data;
  		struct got_pathlist_entry *pi;
  
  		TAILQ_FOREACH(pi, ignorelist, entry) {
  			const char *p, *pattern = pi->path;
  
  			if (strncmp(pattern, "**/", 3) != 0)
  				continue;
  			pattern += 3;
  			p = path;
  			while (*p) {
  				if (fnmatch(pattern, p,
  				    FNM_PATHNAME | FNM_LEADING_DIR)) {
  					/* Retry in next directory. */
  					while (*p && *p != '/')
  						p++;
  					while (*p == '/')
  						p++;
  					continue;
  				}
  				return 1;
  			}
  		}
  	}
  
  	/*
  	 * The ignores pathlist contains ignore lists from children before
  	 * parents, so we can find the most specific ignorelist by walking
  	 * ignores backwards.
  	 */
  	pe = TAILQ_LAST(ignores, got_pathlist_head);
  	while (pe) {
  		if (got_path_is_child(path, pe->path, pe->path_len)) {
  			struct got_pathlist_head *ignorelist = pe->data;
  			struct got_pathlist_entry *pi;
  			TAILQ_FOREACH(pi, ignorelist, entry) {
  				const char *pattern = pi->path;
  				int flags = FNM_LEADING_DIR;
  				if (strstr(pattern, "/**/") == NULL)
  					flags |= FNM_PATHNAME;
  				if (fnmatch(pattern, path, flags))
  					continue;
  				return 1;
  			}
  		}
  		pe = TAILQ_PREV(pe, got_pathlist_head, entry);
  	}
  
  	return 0;
  }
  
  static const struct got_error *
  add_ignores(struct got_pathlist_head *ignores, const char *root_path,
      const char *path, int dirfd, const char *ignores_filename)
  {
  	const struct got_error *err = NULL;
  	char *ignorespath;
  	int fd = -1;
  	FILE *ignoresfile = NULL;
  
  	if (asprintf(&ignorespath, "%s/%s%s%s", root_path, path,
  	    path[0] ? "/" : "", ignores_filename) == -1)
  		return got_error_from_errno("asprintf");
  
  	if (dirfd != -1) {
  		fd = openat(dirfd, ignores_filename,
  		    O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
  		if (fd == -1) {
  			if (errno != ENOENT && errno != EACCES)
  				err = got_error_from_errno2("openat",
  				    ignorespath);
  		} else {
  			ignoresfile = fdopen(fd, "r");
  			if (ignoresfile == NULL) 
  				err = got_error_from_errno2("fdopen",
  				    ignorespath);
  			else {
  				fd = -1;
  				err = read_ignores(ignores, path, ignoresfile);
  			}
  		}
  	} else {
  		ignoresfile = fopen(ignorespath, "re");
  		if (ignoresfile == NULL) {
  			if (errno != ENOENT && errno != EACCES)
  				err = got_error_from_errno2("fopen",
  				    ignorespath);
  		} else
  			err = read_ignores(ignores, path, ignoresfile);
  	}
  
  	if (ignoresfile && fclose(ignoresfile) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", path);
  	if (fd != -1 && close(fd) == -1 && err == NULL)
  		err = got_error_from_errno2("close", path);
  	free(ignorespath);
  	return err;
  }
  
  static const struct got_error *
  status_new(int *ignore, void *arg, struct dirent *de, const char *parent_path,
      int dirfd)
  {
  	const struct got_error *err = NULL;
  	struct diff_dir_cb_arg *a = arg;
  	char *path = NULL;
  
  	if (ignore != NULL)
  		*ignore = 0;
  
  	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
  		return got_error(GOT_ERR_CANCELLED);
  
  	if (parent_path[0]) {
  		if (asprintf(&path, "%s/%s", parent_path, de->d_name) == -1)
  			return got_error_from_errno("asprintf");
  	} else {
  		path = de->d_name;
  	}
  
  	if (de->d_type == DT_DIR) {
  		if (!a->no_ignores && ignore != NULL &&
  		    match_ignores(a->ignores, path))
  			*ignore = 1;
  	} else if (!match_ignores(a->ignores, path) &&
  	    got_path_is_child(path, a->status_path, a->status_path_len))
  		err = (*a->status_cb)(a->status_arg, GOT_STATUS_UNVERSIONED,
  		    GOT_STATUS_NO_CHANGE, path, NULL, NULL, NULL, -1, NULL);
  	if (parent_path[0])
  		free(path);
  	return err;
  }
  
  static const struct got_error *
  status_traverse(void *arg, const char *path, int dirfd)
  {
  	const struct got_error *err = NULL;
  	struct diff_dir_cb_arg *a = arg;
  
  	if (a->no_ignores)
  		return NULL;
  
  	err = add_ignores(a->ignores, a->worktree->root_path,
  	    path, dirfd, ".cvsignore");
  	if (err)
  		return err;
  
  	err = add_ignores(a->ignores, a->worktree->root_path, path,
  	    dirfd, ".gitignore");
  
  	return err;
  }
  
  static const struct got_error *
  report_single_file_status(const char *path, const char *ondisk_path,
      struct got_fileindex *fileindex, got_worktree_status_cb status_cb,
      void *status_arg, struct got_repository *repo, int report_unchanged,
      struct got_pathlist_head *ignores, int no_ignores)
  {
  	struct got_fileindex_entry *ie;
  	struct stat sb;
  
  	ie = got_fileindex_entry_get(fileindex, path, strlen(path));
  	if (ie)
  		return report_file_status(ie, ondisk_path, -1, NULL,
  		    status_cb, status_arg, repo, report_unchanged);
  
  	if (lstat(ondisk_path, &sb) == -1) {
  		if (errno != ENOENT)
  			return got_error_from_errno2("lstat", ondisk_path);
  		return (*status_cb)(status_arg, GOT_STATUS_NONEXISTENT,
  		    GOT_STATUS_NO_CHANGE, path, NULL, NULL, NULL, -1, NULL);
  	}
  
  	if (!no_ignores && match_ignores(ignores, path))
  		return NULL;
  
  	if (S_ISREG(sb.st_mode) || S_ISLNK(sb.st_mode))
  		return (*status_cb)(status_arg, GOT_STATUS_UNVERSIONED,
  		    GOT_STATUS_NO_CHANGE, path, NULL, NULL, NULL, -1, NULL);
  
  	return NULL;
  }
  
  static const struct got_error *
  add_ignores_from_parent_paths(struct got_pathlist_head *ignores,
      const char *root_path, const char *path)
  {
  	const struct got_error *err;
  	char *parent_path, *next_parent_path = NULL;
  
  	err = add_ignores(ignores, root_path, "", -1,
  	    ".cvsignore");
  	if (err)
  		return err;
  
  	err = add_ignores(ignores, root_path, "", -1,
  	    ".gitignore");
  	if (err)
  		return err;
  
  	err = got_path_dirname(&parent_path, path);
  	if (err) {
  		if (err->code == GOT_ERR_BAD_PATH)
  			return NULL; /* cannot traverse parent */
  		return err;
  	}
  	for (;;) {
  		err = add_ignores(ignores, root_path, parent_path, -1,
  		    ".cvsignore");
  		if (err)
  			break;
  		err = add_ignores(ignores, root_path, parent_path, -1,
  		    ".gitignore");
  		if (err)
  			break;
  		err = got_path_dirname(&next_parent_path, parent_path);
  		if (err) {
  			if (err->code == GOT_ERR_BAD_PATH)
  				err = NULL; /* traversed everything */
  			break;
  		}
  		if (got_path_is_root_dir(parent_path))
  			break;
  		free(parent_path);
  		parent_path = next_parent_path;
  		next_parent_path = NULL;
  	}
  
  	free(parent_path);
  	free(next_parent_path);
  	return err;
  }
  
  static const struct got_error *
  worktree_status(struct got_worktree *worktree, const char *path,
      struct got_fileindex *fileindex, struct got_repository *repo,
      got_worktree_status_cb status_cb, void *status_arg,
      got_cancel_cb cancel_cb, void *cancel_arg, int no_ignores,
      int report_unchanged)
  {
  	const struct got_error *err = NULL;
  	int fd = -1;
  	struct got_fileindex_diff_dir_cb fdiff_cb;
  	struct diff_dir_cb_arg arg;
  	char *ondisk_path = NULL;
  	struct got_pathlist_head ignores;
  	struct got_fileindex_entry *ie;
  
  	TAILQ_INIT(&ignores);
  
  	if (asprintf(&ondisk_path, "%s%s%s",
  	    worktree->root_path, path[0] ? "/" : "", path) == -1)
  		return got_error_from_errno("asprintf");
  
  	ie = got_fileindex_entry_get(fileindex, path, strlen(path));
  	if (ie) {
  		err = report_single_file_status(path, ondisk_path,
  		    fileindex, status_cb, status_arg, repo,
  		    report_unchanged, &ignores, no_ignores);
  		goto done;
  	}
  
  	fd = open(ondisk_path, O_RDONLY | O_NOFOLLOW | O_DIRECTORY | O_CLOEXEC);
  	if (fd == -1) {
  		if (errno != ENOTDIR && errno != ENOENT && errno != EACCES &&
  		    !got_err_open_nofollow_on_symlink())
  			err = got_error_from_errno2("open", ondisk_path);
  		else {
  			if (!no_ignores) {
  				err = add_ignores_from_parent_paths(&ignores,
  				    worktree->root_path, ondisk_path);
  				if (err)
  					goto done;
  			}
  			err = report_single_file_status(path, ondisk_path,
  			    fileindex, status_cb, status_arg, repo,
  			    report_unchanged, &ignores, no_ignores);
  		}
  	} else {
  		fdiff_cb.diff_old_new = status_old_new;
  		fdiff_cb.diff_old = status_old;
  		fdiff_cb.diff_new = status_new;
  		fdiff_cb.diff_traverse = status_traverse;
  		arg.fileindex = fileindex;
  		arg.worktree = worktree;
  		arg.status_path = path;
  		arg.status_path_len = strlen(path);
  		arg.repo = repo;
  		arg.status_cb = status_cb;
  		arg.status_arg = status_arg;
  		arg.cancel_cb = cancel_cb;
  		arg.cancel_arg = cancel_arg;
  		arg.report_unchanged = report_unchanged;
  		arg.no_ignores = no_ignores;
  		if (!no_ignores) {
  			err = add_ignores_from_parent_paths(&ignores,
  			    worktree->root_path, path);
  			if (err)
  				goto done;
  		}
  		arg.ignores = &ignores;
  		err = got_fileindex_diff_dir(fileindex, fd,
  		    worktree->root_path, path, repo, &fdiff_cb, &arg);
  	}
  done:
  	free_ignores(&ignores);
  	if (fd != -1 && close(fd) == -1 && err == NULL)
  		err = got_error_from_errno("close");
  	free(ondisk_path);
  	return err;
  }
  
  const struct got_error *
  got_worktree_status(struct got_worktree *worktree,
      struct got_pathlist_head *paths, struct got_repository *repo,
      int no_ignores, got_worktree_status_cb status_cb, void *status_arg,
      got_cancel_cb cancel_cb, void *cancel_arg)
  {
  	const struct got_error *err = NULL;
  	char *fileindex_path = NULL;
  	struct got_fileindex *fileindex = NULL;
  	struct got_pathlist_entry *pe;
  
  	err = open_fileindex(&fileindex, &fileindex_path, worktree);
  	if (err)
  		return err;
  
  	TAILQ_FOREACH(pe, paths, entry) {
  		err = worktree_status(worktree, pe->path, fileindex, repo,
  			status_cb, status_arg, cancel_cb, cancel_arg,
  			no_ignores, 0);
  		if (err)
  			break;
  	}
  	free(fileindex_path);
  	got_fileindex_free(fileindex);
  	return err;
  }
  
  const struct got_error *
  got_worktree_resolve_path(char **wt_path, struct got_worktree *worktree,
      const char *arg)
  {
  	const struct got_error *err = NULL;
  	char *resolved = NULL, *cwd = NULL, *path = NULL;
  	size_t len;
  	struct stat sb;
  	char *abspath = NULL;
  	char canonpath[PATH_MAX];
  
  	*wt_path = NULL;
  
  	cwd = getcwd(NULL, 0);
  	if (cwd == NULL)
  		return got_error_from_errno("getcwd");
  
  	if (lstat(arg, &sb) == -1) {
  		if (errno != ENOENT) {
  			err = got_error_from_errno2("lstat", arg);
  			goto done;
  		}
  		sb.st_mode = 0;
  	}
  	if (S_ISLNK(sb.st_mode)) {
  		/*
  		 * We cannot use realpath(3) with symlinks since we want to
  		 * operate on the symlink itself.
  		 * But we can make the path absolute, assuming it is relative
  		 * to the current working directory, and then canonicalize it.
  		 */
  		if (!got_path_is_absolute(arg)) {
  			if (asprintf(&abspath, "%s/%s", cwd, arg) == -1) {
  				err = got_error_from_errno("asprintf");
  				goto done;
  			}
  
  		}
  		err = got_canonpath(abspath ? abspath : arg, canonpath,
  		    sizeof(canonpath));
  		if (err)
  			goto done;
  		resolved = strdup(canonpath);
  		if (resolved == NULL) {
  			err = got_error_from_errno("strdup");
  			goto done;
  		}
  	} else {
  		resolved = realpath(arg, NULL);
  		if (resolved == NULL) {
  			if (errno != ENOENT) {
  				err = got_error_from_errno2("realpath", arg);
  				goto done;
  			}
  			if (asprintf(&abspath, "%s/%s", cwd, arg) == -1) {
  				err = got_error_from_errno("asprintf");
  				goto done;
  			}
  			err = got_canonpath(abspath, canonpath,
  			    sizeof(canonpath));
  			if (err)
  				goto done;
  			resolved = strdup(canonpath);
  			if (resolved == NULL) {
  				err = got_error_from_errno("strdup");
  				goto done;
  			}
  		}
  	}
  
  	if (strncmp(got_worktree_get_root_path(worktree), resolved,
  	    strlen(got_worktree_get_root_path(worktree)))) {
  		err = got_error_path(resolved, GOT_ERR_BAD_PATH);
  		goto done;
  	}
  
  	if (strlen(resolved) > strlen(got_worktree_get_root_path(worktree))) {
  		err = got_path_skip_common_ancestor(&path,
  		    got_worktree_get_root_path(worktree), resolved);
  		if (err)
  			goto done;
  	} else {
  		path = strdup("");
  		if (path == NULL) {
  			err = got_error_from_errno("strdup");
  			goto done;
  		}
  	}
  
  	/* XXX status walk can't deal with trailing slash! */
  	len = strlen(path);
  	while (len > 0 && path[len - 1] == '/') {
  		path[len - 1] = '\0';
  		len--;
  	}
  done:
  	free(abspath);
  	free(resolved);
  	free(cwd);
  	if (err == NULL)
  		*wt_path = path;
  	else
  		free(path);
  	return err;
  }
  
  struct schedule_addition_args {
  	struct got_worktree *worktree;
  	struct got_fileindex *fileindex;
  	got_worktree_checkout_cb progress_cb;
  	void *progress_arg;
  	struct got_repository *repo;
  };
  
  static const struct got_error *
  schedule_addition(void *arg, unsigned char status, unsigned char staged_status,
      const char *relpath, struct got_object_id *blob_id,
      struct got_object_id *staged_blob_id, struct got_object_id *commit_id,
      int dirfd, const char *de_name)
  {
  	struct schedule_addition_args *a = arg;
  	const struct got_error *err = NULL;
  	struct got_fileindex_entry *ie;
  	struct stat sb;
  	char *ondisk_path;
  
  	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
  	    relpath) == -1)
  		return got_error_from_errno("asprintf");
  
  	ie = got_fileindex_entry_get(a->fileindex, relpath, strlen(relpath));
  	if (ie) {
  		err = get_file_status(&status, &sb, ie, ondisk_path, dirfd,
  		    de_name, a->repo);
  		if (err)
  			goto done;
  		/* Re-adding an existing entry is a no-op. */
  		if (status == GOT_STATUS_ADD)
  			goto done;
  		err = got_error_path(relpath, GOT_ERR_FILE_STATUS);
  		if (err)
  			goto done;
  	}
  
  	if (status != GOT_STATUS_UNVERSIONED) {
  		if (status == GOT_STATUS_NONEXISTENT)
  			err = got_error_set_errno(ENOENT, ondisk_path);
  		else
  			err = got_error_path(ondisk_path, GOT_ERR_FILE_STATUS);
  		goto done;
  	}
  
  	err = got_fileindex_entry_alloc(&ie, relpath);
  	if (err)
  		goto done;
  	err = got_fileindex_entry_update(ie, a->worktree->root_fd,
  	    relpath, NULL, NULL, 1);
  	if (err) {
  		got_fileindex_entry_free(ie);
  		goto done;
  	}
  	err = got_fileindex_entry_add(a->fileindex, ie);
  	if (err) {
  		got_fileindex_entry_free(ie);
  		goto done;
  	}
  done:
  	free(ondisk_path);
  	if (err)
  		return err;
  	if (status == GOT_STATUS_ADD)
  		return NULL;
  	return (*a->progress_cb)(a->progress_arg, GOT_STATUS_ADD, relpath);
  }
  
  const struct got_error *
  got_worktree_schedule_add(struct got_worktree *worktree,
      struct got_pathlist_head *paths,
      got_worktree_checkout_cb progress_cb, void *progress_arg,
      struct got_repository *repo, int no_ignores)
  {
  	struct got_fileindex *fileindex = NULL;
  	char *fileindex_path = NULL;
  	const struct got_error *err = NULL, *sync_err, *unlockerr;
  	struct got_pathlist_entry *pe;
  	struct schedule_addition_args saa;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = open_fileindex(&fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	saa.worktree = worktree;
  	saa.fileindex = fileindex;
  	saa.progress_cb = progress_cb;
  	saa.progress_arg = progress_arg;
  	saa.repo = repo;
  
  	TAILQ_FOREACH(pe, paths, entry) {
  		err = worktree_status(worktree, pe->path, fileindex, repo,
  			schedule_addition, &saa, NULL, NULL, no_ignores, 0);
  		if (err)
  			break;
  	}
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	free(fileindex_path);
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  struct schedule_deletion_args {
  	struct got_worktree *worktree;
  	struct got_fileindex *fileindex;
  	got_worktree_delete_cb progress_cb;
  	void *progress_arg;
  	struct got_repository *repo;
  	int delete_local_mods;
  	int keep_on_disk;
  	int ignore_missing_paths;
  	const char *status_codes;
  };
  
  static const struct got_error *
  schedule_for_deletion(void *arg, unsigned char status,
      unsigned char staged_status, const char *relpath,
      struct got_object_id *blob_id, struct got_object_id *staged_blob_id,
      struct got_object_id *commit_id, int dirfd, const char *de_name)
  {
  	struct schedule_deletion_args *a = arg;
  	const struct got_error *err = NULL;
  	struct got_fileindex_entry *ie = NULL;
  	struct stat sb;
  	char *ondisk_path;
  
  	if (status == GOT_STATUS_NONEXISTENT) {
  		if (a->ignore_missing_paths)
  			return NULL;
  		return got_error_set_errno(ENOENT, relpath);
  	}
  
  	ie = got_fileindex_entry_get(a->fileindex, relpath, strlen(relpath));
  	if (ie == NULL)
  		return got_error_path(relpath, GOT_ERR_FILE_STATUS);
  
  	staged_status = get_staged_status(ie);
  	if (staged_status != GOT_STATUS_NO_CHANGE) {
  		if (staged_status == GOT_STATUS_DELETE)
  			return NULL;
  		return got_error_path(relpath, GOT_ERR_FILE_STAGED);
  	}
  
  	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
  	    relpath) == -1)
  		return got_error_from_errno("asprintf");
  
  	err = get_file_status(&status, &sb, ie, ondisk_path, dirfd, de_name,
  	    a->repo);
  	if (err)
  		goto done;
  
  	if (a->status_codes) {
  		size_t ncodes = strlen(a->status_codes);
  		int i;
  		for (i = 0; i < ncodes ; i++) {
  			if (status == a->status_codes[i])
  				break;
  		}
  		if (i == ncodes) { 
  			/* Do not delete files in non-matching status. */
  			free(ondisk_path);
  			return NULL;
  		}
  		if (a->status_codes[i] != GOT_STATUS_MODIFY &&
  		    a->status_codes[i] != GOT_STATUS_MISSING) {
  			static char msg[64];
  			snprintf(msg, sizeof(msg),
  			    "invalid status code '%c'", a->status_codes[i]);
  			err = got_error_msg(GOT_ERR_FILE_STATUS, msg);
  			goto done;
  		}
  	}
  
  	if (status != GOT_STATUS_NO_CHANGE) {
  		if (status == GOT_STATUS_DELETE)
  			goto done;
  		if (status == GOT_STATUS_MODIFY && !a->delete_local_mods) {
  			err = got_error_path(relpath, GOT_ERR_FILE_MODIFIED);
  			goto done;
  		}
  		if (status == GOT_STATUS_MISSING && !a->ignore_missing_paths) {
  			err = got_error_set_errno(ENOENT, relpath);
  			goto done;
  		}
  		if (status != GOT_STATUS_MODIFY &&
  		    status != GOT_STATUS_MISSING) {
  			err = got_error_path(relpath, GOT_ERR_FILE_STATUS);
  			goto done;
  		}
  	}
  
  	if (!a->keep_on_disk && status != GOT_STATUS_MISSING) {
  		size_t root_len;
  
  		if (dirfd != -1) {
  			if (unlinkat(dirfd, de_name, 0) != 0) {
  				err = got_error_from_errno2("unlinkat",
  				    ondisk_path);
  				goto done;
  			}
  		} else if (unlink(ondisk_path) != 0) {
  			err = got_error_from_errno2("unlink", ondisk_path);
  			goto done;
  		}
  
  		root_len = strlen(a->worktree->root_path);
  		do {
  			char *parent;
  			err = got_path_dirname(&parent, ondisk_path);
  			if (err)
  				goto done;
  			free(ondisk_path);
  			ondisk_path = parent;
  			if (rmdir(ondisk_path) == -1) {
  				if (errno != ENOTEMPTY)
  					err = got_error_from_errno2("rmdir",
  					    ondisk_path);
  				break;
  			}
  		} while (got_path_cmp(ondisk_path, a->worktree->root_path,
  		    strlen(ondisk_path), root_len) != 0);
  	}
  
  	got_fileindex_entry_mark_deleted_from_disk(ie);
  done:
  	free(ondisk_path);
  	if (err)
  		return err;
  	if (status == GOT_STATUS_DELETE)
  		return NULL;
  	return (*a->progress_cb)(a->progress_arg, GOT_STATUS_DELETE,
  	    staged_status, relpath);
  }
  
  const struct got_error *
  got_worktree_schedule_delete(struct got_worktree *worktree,
      struct got_pathlist_head *paths, int delete_local_mods,
      const char *status_codes,
      got_worktree_delete_cb progress_cb, void *progress_arg,
      struct got_repository *repo, int keep_on_disk, int ignore_missing_paths)
  {
  	struct got_fileindex *fileindex = NULL;
  	char *fileindex_path = NULL;
  	const struct got_error *err = NULL, *sync_err, *unlockerr;
  	struct got_pathlist_entry *pe;
  	struct schedule_deletion_args sda;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = open_fileindex(&fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	sda.worktree = worktree;
  	sda.fileindex = fileindex;
  	sda.progress_cb = progress_cb;
  	sda.progress_arg = progress_arg;
  	sda.repo = repo;
  	sda.delete_local_mods = delete_local_mods;
  	sda.keep_on_disk = keep_on_disk;
  	sda.ignore_missing_paths = ignore_missing_paths;
  	sda.status_codes = status_codes;
  
  	TAILQ_FOREACH(pe, paths, entry) {
  		err = worktree_status(worktree, pe->path, fileindex, repo,
  			schedule_for_deletion, &sda, NULL, NULL, 1, 1);
  		if (err)
  			break;
  	}
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	free(fileindex_path);
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  static const struct got_error *
  copy_one_line(FILE *infile, FILE *outfile, FILE *rejectfile)
  {
  	const struct got_error *err = NULL;
  	char *line = NULL;
  	size_t linesize = 0, n;
  	ssize_t linelen;
  
  	linelen = getline(&line, &linesize, infile);
  	if (linelen == -1) {
  		if (ferror(infile)) {
  			err = got_error_from_errno("getline");
  			goto done;
  		}
  		return NULL;
  	}
  	if (outfile) {
  		n = fwrite(line, 1, linelen, outfile);
  		if (n != linelen) {
  			err = got_ferror(outfile, GOT_ERR_IO);
  			goto done;
  		}
  	}
  	if (rejectfile) {
  		n = fwrite(line, 1, linelen, rejectfile);
  		if (n != linelen)
  			err = got_ferror(outfile, GOT_ERR_IO);
  	}
  done:
  	free(line);
  	return err;
  }
  
  static const struct got_error *
  skip_one_line(FILE *f)
  {
  	char *line = NULL;
  	size_t linesize = 0;
  	ssize_t linelen;
  
  	linelen = getline(&line, &linesize, f);
  	if (linelen == -1) {
  		if (ferror(f))
  			return got_error_from_errno("getline");
  		return NULL;
  	}
  	free(line);
  	return NULL;
  }
  
  static const struct got_error *
  copy_change(FILE *f1, FILE *f2, int *line_cur1, int *line_cur2,
      int start_old, int end_old, int start_new, int end_new,
      FILE *outfile, FILE *rejectfile)
  {
  	const struct got_error *err;
  
  	/* Copy old file's lines leading up to patch. */
  	while (!feof(f1) && *line_cur1 < start_old) {
  		err = copy_one_line(f1, outfile, NULL);
  		if (err)
  			return err;
  		(*line_cur1)++;
  	}
  	/* Skip new file's lines leading up to patch. */
  	while (!feof(f2) && *line_cur2 < start_new) {
  		if (rejectfile)
  			err = copy_one_line(f2, NULL, rejectfile);
  		else
  			err = skip_one_line(f2);
  		if (err)
  			return err;
  		(*line_cur2)++;
  	}
  	/* Copy patched lines. */
  	while (!feof(f2) && *line_cur2 <= end_new) {
  		err = copy_one_line(f2, outfile, NULL);
  		if (err)
  			return err;
  		(*line_cur2)++;
  	}
  	/* Skip over old file's replaced lines. */
  	while (!feof(f1) && *line_cur1 <= end_old) {
  		if (rejectfile)
  			err = copy_one_line(f1, NULL, rejectfile);
  		else
  			err = skip_one_line(f1);
  		if (err)
  			return err;
  		(*line_cur1)++;
  	}
  
  	return NULL;
  }
  
  static const struct got_error *
  copy_remaining_content(FILE *f1, FILE *f2, int *line_cur1, int *line_cur2,
      FILE *outfile, FILE *rejectfile)
  {
  	const struct got_error *err;
  
  	if (outfile) {
  		/* Copy old file's lines until EOF. */
  		while (!feof(f1)) {
  			err = copy_one_line(f1, outfile, NULL);
  			if (err)
  				return err;
  			(*line_cur1)++;
  		}
  	}
  	if (rejectfile) {
  		/* Copy new file's lines until EOF. */
  		while (!feof(f2)) {
  			err = copy_one_line(f2, NULL, rejectfile);
  			if (err)
  				return err;
  			(*line_cur2)++;
  		}
  	}
  
  	return NULL;
  }
  
  static const struct got_error *
  apply_or_reject_change(int *choice, int *nchunks_used,
      struct diff_result *diff_result, int n,
      const char *relpath, FILE *f1, FILE *f2, int *line_cur1, int *line_cur2,
      FILE *outfile, FILE *rejectfile, int changeno, int nchanges,
      got_worktree_patch_cb patch_cb, void *patch_arg)
  {
  	const struct got_error *err = NULL;
  	struct diff_chunk_context cc = {}; 
  	int start_old, end_old, start_new, end_new;
  	FILE *hunkfile;
  	struct diff_output_unidiff_state *diff_state;
  	struct diff_input_info diff_info;
  	int rc;
  
  	*choice = GOT_PATCH_CHOICE_NONE;
  
  	/* Get changed line numbers without context lines for copy_change(). */
  	diff_chunk_context_load_change(&cc, NULL, diff_result, n, 0);
  	start_old = cc.left.start;
  	end_old = cc.left.end;
  	start_new = cc.right.start;
  	end_new = cc.right.end;
  
  	/* Get the same change with context lines for display. */
  	memset(&cc, 0, sizeof(cc));
  	diff_chunk_context_load_change(&cc, nchunks_used, diff_result, n, 3);
  
  	memset(&diff_info, 0, sizeof(diff_info));
  	diff_info.left_path = relpath;
  	diff_info.right_path = relpath;
  
  	diff_state = diff_output_unidiff_state_alloc();
  	if (diff_state == NULL)
  		return got_error_set_errno(ENOMEM,
  		    "diff_output_unidiff_state_alloc");
  
  	hunkfile = got_opentemp();
  	if (hunkfile == NULL) {
  		err = got_error_from_errno("got_opentemp");
  		goto done;
  	}
  
  	rc = diff_output_unidiff_chunk(NULL, hunkfile, diff_state, &diff_info,
  	    diff_result, &cc);
  	if (rc != DIFF_RC_OK) {
  		err = got_error_set_errno(rc, "diff_output_unidiff_chunk");
  		goto done;
  	}
  
  	if (fseek(hunkfile, 0L, SEEK_SET) == -1) {
  		err = got_ferror(hunkfile, GOT_ERR_IO);
  		goto done;
  	}
  
  	err = (*patch_cb)(choice, patch_arg, GOT_STATUS_MODIFY, relpath,
  	    hunkfile, changeno, nchanges);
  	if (err)
  		goto done;
  
  	switch (*choice) {
  	case GOT_PATCH_CHOICE_YES:
  		err = copy_change(f1, f2, line_cur1, line_cur2, start_old,
  		    end_old, start_new, end_new, outfile, rejectfile);
  		break;
  	case GOT_PATCH_CHOICE_NO:
  		err = copy_change(f1, f2, line_cur1, line_cur2, start_old,
  		    end_old, start_new, end_new, rejectfile, outfile);
  		break;
  	case GOT_PATCH_CHOICE_QUIT:
  		break;
  	default:
  		err = got_error(GOT_ERR_PATCH_CHOICE);
  		break;
  	}
  done:
  	diff_output_unidiff_state_free(diff_state);
  	if (hunkfile && fclose(hunkfile) == EOF && err == NULL)
  		err = got_error_from_errno("fclose");
  	return err;
  }
  
  struct revert_file_args {
  	struct got_worktree *worktree;
  	struct got_fileindex *fileindex;
  	got_worktree_checkout_cb progress_cb;
  	void *progress_arg;
  	got_worktree_patch_cb patch_cb;
  	void *patch_arg;
  	struct got_repository *repo;
  	int unlink_added_files;
  };
  
  static const struct got_error *
  create_patched_content(char **path_outfile, int reverse_patch,
      struct got_object_id *blob_id, const char *path2,
      int dirfd2, const char *de_name2,
      const char *relpath, struct got_repository *repo,
      got_worktree_patch_cb patch_cb, void *patch_arg)
  {
  	const struct got_error *err, *free_err;
  	struct got_blob_object *blob = NULL;
  	FILE *f1 = NULL, *f2 = NULL, *outfile = NULL;
  	int fd2 = -1;
  	char link_target[PATH_MAX];
  	ssize_t link_len = 0;
  	char *path1 = NULL, *id_str = NULL;
  	struct stat sb2;
  	struct got_diffreg_result *diffreg_result = NULL;
  	int line_cur1 = 1, line_cur2 = 1, have_content = 0;
  	int i = 0, n = 0, nchunks_used = 0, nchanges = 0;
  
  	*path_outfile = NULL;
  
  	err = got_object_id_str(&id_str, blob_id);
  	if (err)
  		return err;
  
  	if (dirfd2 != -1) {
  		fd2 = openat(dirfd2, de_name2,
  		    O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
  		if (fd2 == -1) {
  			if (!got_err_open_nofollow_on_symlink()) {
  				err = got_error_from_errno2("openat", path2);
  				goto done;
  			}
  			link_len = readlinkat(dirfd2, de_name2,
  			    link_target, sizeof(link_target));
  			if (link_len == -1) {
  				return got_error_from_errno2("readlinkat",
  				    path2);
  			}
  			sb2.st_mode = S_IFLNK;
  			sb2.st_size = link_len;
  		}
  	} else {
  		fd2 = open(path2, O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
  		if (fd2 == -1) {
  			if (!got_err_open_nofollow_on_symlink()) {
  				err = got_error_from_errno2("open", path2);
  				goto done;
  			}
  			link_len = readlink(path2, link_target,
  			    sizeof(link_target));
  			if (link_len == -1)
  				return got_error_from_errno2("readlink", path2);
  			sb2.st_mode = S_IFLNK;
  			sb2.st_size = link_len;
  		}
  	}
  	if (fd2 != -1) {
  		if (fstat(fd2, &sb2) == -1) {
  			err = got_error_from_errno2("fstat", path2);
  			goto done;
  		}
  
  		f2 = fdopen(fd2, "r");
  		if (f2 == NULL) {
  			err = got_error_from_errno2("fdopen", path2);
  			goto done;
  		}
  		fd2 = -1;
  	} else {
  		size_t n;
  		f2 = got_opentemp();
  		if (f2 == NULL) {
  			err = got_error_from_errno2("got_opentemp", path2);
  			goto done;
  		}
  		n = fwrite(link_target, 1, link_len, f2);
  		if (n != link_len) {
  			err = got_ferror(f2, GOT_ERR_IO);
  			goto done;
  		}
  		if (fflush(f2) == EOF) {
  			err = got_error_from_errno("fflush");
  			goto done;
  		}
  		rewind(f2);
  	}
  
  	err = got_object_open_as_blob(&blob, repo, blob_id, 8192);
  	if (err)
  		goto done;
  
  	err = got_opentemp_named(&path1, &f1, "got-patched-blob");
  	if (err)
  		goto done;
  
  	err = got_object_blob_dump_to_file(NULL, NULL, NULL, f1, blob);
  	if (err)
  		goto done;
  
  	err = got_diff_files(&diffreg_result, f1, id_str, f2, path2, 3, 0, 1,
  	    NULL);
  	if (err)
  		goto done;
  
  	err = got_opentemp_named(path_outfile, &outfile, "got-patched-content");
  	if (err)
  		goto done;
  
  	if (fseek(f1, 0L, SEEK_SET) == -1)
  		return got_ferror(f1, GOT_ERR_IO);
  	if (fseek(f2, 0L, SEEK_SET) == -1)
  		return got_ferror(f2, GOT_ERR_IO);
  
  	/* Count the number of actual changes in the diff result. */
  	for (n = 0; n < diffreg_result->result->chunks.len; n += nchunks_used) {
  		struct diff_chunk_context cc = {}; 
  		diff_chunk_context_load_change(&cc, &nchunks_used,
  		    diffreg_result->result, n, 0);
  		nchanges++;
  	}
  	for (n = 0; n < diffreg_result->result->chunks.len; n += nchunks_used) {
  		int choice;
  		err = apply_or_reject_change(&choice, &nchunks_used,
  		    diffreg_result->result, n, relpath, f1, f2,
  		    &line_cur1, &line_cur2,
  		    reverse_patch ? NULL : outfile,
  		    reverse_patch ? outfile : NULL,
  		    ++i, nchanges, patch_cb, patch_arg);
  		if (err)
  			goto done;
  		if (choice == GOT_PATCH_CHOICE_YES)
  			have_content = 1;
  		else if (choice == GOT_PATCH_CHOICE_QUIT)
  			break;
  	}
  	if (have_content) {
  		err = copy_remaining_content(f1, f2, &line_cur1, &line_cur2,
  		    reverse_patch ? NULL : outfile,
  		    reverse_patch ? outfile : NULL);
  		if (err)
  			goto done;
  
  		if (!S_ISLNK(sb2.st_mode)) {
  			if (fchmod(fileno(outfile), sb2.st_mode) == -1) {
  				err = got_error_from_errno2("fchmod", path2);
  				goto done;
  			}
  		}
  	}
  done:
  	free(id_str);
  	if (blob)
  		got_object_blob_close(blob);
  	free_err = got_diffreg_result_free(diffreg_result);
  	if (err == NULL)
  		err = free_err;
  	if (f1 && fclose(f1) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", path1);
  	if (f2 && fclose(f2) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", path2);
  	if (fd2 != -1 && close(fd2) == -1 && err == NULL)
  		err = got_error_from_errno2("close", path2);
  	if (outfile && fclose(outfile) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", *path_outfile);
  	if (path1 && unlink(path1) == -1 && err == NULL)
  		err = got_error_from_errno2("unlink", path1);
  	if (err || !have_content) {
  		if (*path_outfile && unlink(*path_outfile) == -1 && err == NULL)
  			err = got_error_from_errno2("unlink", *path_outfile);
  		free(*path_outfile);
  		*path_outfile = NULL;
  	}
  	free(path1);
  	return err;
  }
  
  static const struct got_error *
  revert_file(void *arg, unsigned char status, unsigned char staged_status,
      const char *relpath, struct got_object_id *blob_id,
      struct got_object_id *staged_blob_id, struct got_object_id *commit_id,
      int dirfd, const char *de_name)
  {
  	struct revert_file_args *a = arg;
  	const struct got_error *err = NULL;
  	char *parent_path = NULL;
  	struct got_fileindex_entry *ie;
  	struct got_commit_object *base_commit = NULL;
  	struct got_tree_object *tree = NULL;
  	struct got_object_id *tree_id = NULL;
  	const struct got_tree_entry *te = NULL;
  	char *tree_path = NULL, *te_name;
  	char *ondisk_path = NULL, *path_content = NULL;
  	struct got_blob_object *blob = NULL;
  
  	/* Reverting a staged deletion is a no-op. */
  	if (status == GOT_STATUS_DELETE &&
  	    staged_status != GOT_STATUS_NO_CHANGE)
  		return NULL;
  
  	if (status == GOT_STATUS_UNVERSIONED)
  		return (*a->progress_cb)(a->progress_arg,
  		    GOT_STATUS_UNVERSIONED, relpath);
  
  	ie = got_fileindex_entry_get(a->fileindex, relpath, strlen(relpath));
  	if (ie == NULL)
  		return got_error_path(relpath, GOT_ERR_BAD_PATH);
  
  	/* Construct in-repository path of tree which contains this blob. */
  	err = got_path_dirname(&parent_path, ie->path);
  	if (err) {
  		if (err->code != GOT_ERR_BAD_PATH)
  			goto done;
  		parent_path = strdup("/");
  		if (parent_path == NULL) {
  			err = got_error_from_errno("strdup");
  			goto done;
  		}
  	}
  	if (got_path_is_root_dir(a->worktree->path_prefix)) {
  		tree_path = strdup(parent_path);
  		if (tree_path == NULL) {
  			err = got_error_from_errno("strdup");
  			goto done;
  		}
  	} else {
  		if (got_path_is_root_dir(parent_path)) {
  			tree_path = strdup(a->worktree->path_prefix);
  			if (tree_path == NULL) {
  				err = got_error_from_errno("strdup");
  				goto done;
  			}
  		} else {
  			if (asprintf(&tree_path, "%s/%s",
  			    a->worktree->path_prefix, parent_path) == -1) {
  				err = got_error_from_errno("asprintf");
  				goto done;
  			}
  		}
  	}
  
  	err = got_object_open_as_commit(&base_commit, a->repo,
  	    a->worktree->base_commit_id);
  	if (err)
  		goto done;
  
  	err = got_object_id_by_path(&tree_id, a->repo, base_commit, tree_path);
  	if (err) {
  		if (!(err->code == GOT_ERR_NO_TREE_ENTRY &&
  		    (status == GOT_STATUS_ADD ||
  		    staged_status == GOT_STATUS_ADD)))
  			goto done;
  	} else {
  		err = got_object_open_as_tree(&tree, a->repo, tree_id);
  		if (err)
  			goto done;
  
  		err = got_path_basename(&te_name, ie->path);
  		if (err)
  			goto done;
  
  		te = got_object_tree_find_entry(tree, te_name);
  		free(te_name);
  		if (te == NULL && status != GOT_STATUS_ADD &&
  		    staged_status != GOT_STATUS_ADD) {
  			err = got_error_path(ie->path, GOT_ERR_NO_TREE_ENTRY);
  			goto done;
  		}
  	}
  
  	switch (status) {
  	case GOT_STATUS_ADD:
  		if (a->patch_cb) {
  			int choice = GOT_PATCH_CHOICE_NONE;
  			err = (*a->patch_cb)(&choice, a->patch_arg,
  			    status, ie->path, NULL, 1, 1);
  			if (err)
  				goto done;
  			if (choice != GOT_PATCH_CHOICE_YES)
  				break;
  		}
  		err = (*a->progress_cb)(a->progress_arg, GOT_STATUS_REVERT,
  		    ie->path);
  		if (err)
  			goto done;
  		got_fileindex_entry_remove(a->fileindex, ie);
  		if (a->unlink_added_files) {
  			if (asprintf(&ondisk_path, "%s/%s",
  			    got_worktree_get_root_path(a->worktree),
  			    relpath) == -1) {
  				err = got_error_from_errno("asprintf");
  				goto done;
  			}
  			if (unlink(ondisk_path) == -1) {
  				err = got_error_from_errno2("unlink",
  				    ondisk_path);
  				break;
  			}
  		}
  		break;
  	case GOT_STATUS_DELETE:
  		if (a->patch_cb) {
  			int choice = GOT_PATCH_CHOICE_NONE;
  			err = (*a->patch_cb)(&choice, a->patch_arg,
  			    status, ie->path, NULL, 1, 1);
  			if (err)
  				goto done;
  			if (choice != GOT_PATCH_CHOICE_YES)
  				break;
  		}
  		/* fall through */
  	case GOT_STATUS_MODIFY:
  	case GOT_STATUS_MODE_CHANGE:
  	case GOT_STATUS_CONFLICT:
  	case GOT_STATUS_MISSING: {
  		struct got_object_id id;
  		if (staged_status == GOT_STATUS_ADD ||
  		    staged_status == GOT_STATUS_MODIFY) {
  			memcpy(id.sha1, ie->staged_blob_sha1,
  			    SHA1_DIGEST_LENGTH);
  		} else
  			memcpy(id.sha1, ie->blob_sha1,
  			    SHA1_DIGEST_LENGTH);
  		err = got_object_open_as_blob(&blob, a->repo, &id, 8192);
  		if (err)
  			goto done;
  
  		if (asprintf(&ondisk_path, "%s/%s",
  		    got_worktree_get_root_path(a->worktree), relpath) == -1) {
  			err = got_error_from_errno("asprintf");
  			goto done;
  		}
  
  		if (a->patch_cb && (status == GOT_STATUS_MODIFY ||
  		    status == GOT_STATUS_CONFLICT)) {
  			int is_bad_symlink = 0;
  			err = create_patched_content(&path_content, 1, &id,
  			    ondisk_path, dirfd, de_name, ie->path, a->repo,
  			    a->patch_cb, a->patch_arg);
  			if (err || path_content == NULL)
  				break;
  			if (te && S_ISLNK(te->mode)) {
  				if (unlink(path_content) == -1) {
  					err = got_error_from_errno2("unlink",
  					    path_content);
  					break;
  				}
  				err = install_symlink(&is_bad_symlink,
  				    a->worktree, ondisk_path, ie->path,
  				    blob, 0, 1, 0, 0, a->repo,
  				    a->progress_cb, a->progress_arg);
  			} else {
  				if (rename(path_content, ondisk_path) == -1) {
  					err = got_error_from_errno3("rename",
  					    path_content, ondisk_path);
  					goto done;
  				}
  			}
  		} else {
  			int is_bad_symlink = 0;
  			if (te && S_ISLNK(te->mode)) {
  				err = install_symlink(&is_bad_symlink,
  				    a->worktree, ondisk_path, ie->path,
  				    blob, 0, 1, 0, 0, a->repo,
  				    a->progress_cb, a->progress_arg);
  			} else {
  				err = install_blob(a->worktree, ondisk_path,
  				    ie->path,
  				    te ? te->mode : GOT_DEFAULT_FILE_MODE,
  				    got_fileindex_perms_to_st(ie), blob,
  				    0, 1, 0, 0, a->repo,
  				    a->progress_cb, a->progress_arg);
  			}
  			if (err)
  				goto done;
  			if (status == GOT_STATUS_DELETE ||
  			    status == GOT_STATUS_MODE_CHANGE) {
  				err = got_fileindex_entry_update(ie,
  				    a->worktree->root_fd, relpath,
  				    blob->id.sha1,
  				    a->worktree->base_commit_id->sha1, 1);
  				if (err)
  					goto done;
  			}
  			if (is_bad_symlink) {
  				got_fileindex_entry_filetype_set(ie,
  				    GOT_FILEIDX_MODE_BAD_SYMLINK);
  			}
  		}
  		break;
  	}
  	default:
  		break;
  	}
  done:
  	free(ondisk_path);
  	free(path_content);
  	free(parent_path);
  	free(tree_path);
  	if (blob)
  		got_object_blob_close(blob);
  	if (tree)
  		got_object_tree_close(tree);
  	free(tree_id);
  	if (base_commit)
  		got_object_commit_close(base_commit);
  	return err;
  }
  
  const struct got_error *
  got_worktree_revert(struct got_worktree *worktree,
      struct got_pathlist_head *paths,
      got_worktree_checkout_cb progress_cb, void *progress_arg,
      got_worktree_patch_cb patch_cb, void *patch_arg,
      struct got_repository *repo)
  {
  	struct got_fileindex *fileindex = NULL;
  	char *fileindex_path = NULL;
  	const struct got_error *err = NULL, *unlockerr = NULL;
  	const struct got_error *sync_err = NULL;
  	struct got_pathlist_entry *pe;
  	struct revert_file_args rfa;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = open_fileindex(&fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	rfa.worktree = worktree;
  	rfa.fileindex = fileindex;
  	rfa.progress_cb = progress_cb;
  	rfa.progress_arg = progress_arg;
  	rfa.patch_cb = patch_cb;
  	rfa.patch_arg = patch_arg;
  	rfa.repo = repo;
  	rfa.unlink_added_files = 0;
  	TAILQ_FOREACH(pe, paths, entry) {
  		err = worktree_status(worktree, pe->path, fileindex, repo,
  		    revert_file, &rfa, NULL, NULL, 1, 0);
  		if (err)
  			break;
  	}
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	free(fileindex_path);
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  static void
  free_commitable(struct got_commitable *ct)
  {
  	free(ct->path);
  	free(ct->in_repo_path);
  	free(ct->ondisk_path);
  	free(ct->blob_id);
  	free(ct->base_blob_id);
  	free(ct->staged_blob_id);
  	free(ct->base_commit_id);
  	free(ct);
  }
  
  struct collect_commitables_arg {
  	struct got_pathlist_head *commitable_paths;
  	struct got_repository *repo;
  	struct got_worktree *worktree;
  	struct got_fileindex *fileindex;
  	int have_staged_files;
  	int allow_bad_symlinks;
  };
  
  static const struct got_error *
  collect_commitables(void *arg, unsigned char status,
      unsigned char staged_status, const char *relpath,
      struct got_object_id *blob_id, struct got_object_id *staged_blob_id,
      struct got_object_id *commit_id, int dirfd, const char *de_name)
  {
  	struct collect_commitables_arg *a = arg;
  	const struct got_error *err = NULL;
  	struct got_commitable *ct = NULL;
  	struct got_pathlist_entry *new = NULL;
  	char *parent_path = NULL, *path = NULL;
  	struct stat sb;
  
  	if (a->have_staged_files) {
  		if (staged_status != GOT_STATUS_MODIFY &&
  		    staged_status != GOT_STATUS_ADD &&
  		    staged_status != GOT_STATUS_DELETE)
  			return NULL;
  	} else {
  		if (status == GOT_STATUS_CONFLICT)
  			return got_error(GOT_ERR_COMMIT_CONFLICT);
  
  		if (status != GOT_STATUS_MODIFY &&
  		    status != GOT_STATUS_MODE_CHANGE &&
  		    status != GOT_STATUS_ADD &&
  		    status != GOT_STATUS_DELETE)
  			return NULL;
  	}
  
  	if (asprintf(&path, "/%s", relpath) == -1) {
  		err = got_error_from_errno("asprintf");
  		goto done;
  	}
  	if (strcmp(path, "/") == 0) {
  		parent_path = strdup("");
  		if (parent_path == NULL)
  			return got_error_from_errno("strdup");
  	} else {
  		err = got_path_dirname(&parent_path, path);
  		if (err)
  			return err;
  	}
  
  	ct = calloc(1, sizeof(*ct));
  	if (ct == NULL) {
  		err = got_error_from_errno("calloc");
  		goto done;
  	}
  
  	if (asprintf(&ct->ondisk_path, "%s/%s", a->worktree->root_path,
  	    relpath) == -1) {
  		err = got_error_from_errno("asprintf");
  		goto done;
  	}
  
  	if (staged_status == GOT_STATUS_ADD ||
  	    staged_status == GOT_STATUS_MODIFY) {
  		struct got_fileindex_entry *ie;
  		ie = got_fileindex_entry_get(a->fileindex, path, strlen(path));
  		switch (got_fileindex_entry_staged_filetype_get(ie)) {
  		case GOT_FILEIDX_MODE_REGULAR_FILE:
  		case GOT_FILEIDX_MODE_BAD_SYMLINK:
  			ct->mode = S_IFREG;
  			break;
  		case GOT_FILEIDX_MODE_SYMLINK:
  			ct->mode = S_IFLNK;
  			break;
  		default:
  			err = got_error_path(path, GOT_ERR_BAD_FILETYPE);
  			goto done;
  		}
  		ct->mode |= got_fileindex_entry_perms_get(ie);
  	} else if (status != GOT_STATUS_DELETE &&
  	    staged_status != GOT_STATUS_DELETE) {
  		if (dirfd != -1) {
  			if (fstatat(dirfd, de_name, &sb,
  			    AT_SYMLINK_NOFOLLOW) == -1) {
  				err = got_error_from_errno2("fstatat",
  				    ct->ondisk_path);
  				goto done;
  			}
  		} else if (lstat(ct->ondisk_path, &sb) == -1) {
  			err = got_error_from_errno2("lstat", ct->ondisk_path);
  			goto done;
  		}
  		ct->mode = sb.st_mode;
  	}
  
  	if (asprintf(&ct->in_repo_path, "%s%s%s", a->worktree->path_prefix,
  	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
  	    relpath) == -1) {
  		err = got_error_from_errno("asprintf");
  		goto done;
  	}
  
  	if (S_ISLNK(ct->mode) && staged_status == GOT_STATUS_NO_CHANGE &&
  	    status == GOT_STATUS_ADD && !a->allow_bad_symlinks) {
  		int is_bad_symlink;
  		char target_path[PATH_MAX];
  		ssize_t target_len;
  		target_len = readlink(ct->ondisk_path, target_path,
  		    sizeof(target_path));
  		if (target_len == -1) {
  			err = got_error_from_errno2("readlink",
  			    ct->ondisk_path);
  			goto done;
  		}
  		err = is_bad_symlink_target(&is_bad_symlink, target_path,
  		    target_len, ct->ondisk_path, a->worktree->root_path);
  		if (err)
  			goto done;
  		if (is_bad_symlink) {
  			err = got_error_path(ct->ondisk_path,
  			    GOT_ERR_BAD_SYMLINK);
  			goto done;
  		}
  	}
  
  
  	ct->status = status;
  	ct->staged_status = staged_status;
  	ct->blob_id = NULL; /* will be filled in when blob gets created */
  	if (ct->status != GOT_STATUS_ADD &&
  	    ct->staged_status != GOT_STATUS_ADD) {
  		ct->base_blob_id = got_object_id_dup(blob_id);
  		if (ct->base_blob_id == NULL) {
  			err = got_error_from_errno("got_object_id_dup");
  			goto done;
  		}
  		ct->base_commit_id = got_object_id_dup(commit_id);
  		if (ct->base_commit_id == NULL) {
  			err = got_error_from_errno("got_object_id_dup");
  			goto done;
  		}
  	}
  	if (ct->staged_status == GOT_STATUS_ADD ||
  	    ct->staged_status == GOT_STATUS_MODIFY) {
  		ct->staged_blob_id = got_object_id_dup(staged_blob_id);
  		if (ct->staged_blob_id == NULL) {
  			err = got_error_from_errno("got_object_id_dup");
  			goto done;
  		}
  	}
  	ct->path = strdup(path);
  	if (ct->path == NULL) {
  		err = got_error_from_errno("strdup");
  		goto done;
  	}
  	err = got_pathlist_insert(&new, a->commitable_paths, ct->path, ct);
  done:
  	if (ct && (err || new == NULL))
  		free_commitable(ct);
  	free(parent_path);
  	free(path);
  	return err;
  }
  
  static const struct got_error *write_tree(struct got_object_id **, int *,
      struct got_tree_object *, const char *, struct got_pathlist_head *,
      got_worktree_status_cb status_cb, void *status_arg,
      struct got_repository *);
  
  static const struct got_error *
  write_subtree(struct got_object_id **new_subtree_id, int *nentries,
      struct got_tree_entry *te, const char *parent_path,
      struct got_pathlist_head *commitable_paths,
      got_worktree_status_cb status_cb, void *status_arg,
      struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	struct got_tree_object *subtree;
  	char *subpath;
  
  	if (asprintf(&subpath, "%s%s%s", parent_path,
  	    got_path_is_root_dir(parent_path) ? "" : "/", te->name) == -1)
  		return got_error_from_errno("asprintf");
  
  	err = got_object_open_as_tree(&subtree, repo, &te->id);
  	if (err)
  		return err;
  
  	err = write_tree(new_subtree_id, nentries, subtree, subpath,
  	    commitable_paths, status_cb, status_arg, repo);
  	got_object_tree_close(subtree);
  	free(subpath);
  	return err;
  }
  
  static const struct got_error *
  match_ct_parent_path(int *match, struct got_commitable *ct, const char *path)
  {
  	const struct got_error *err = NULL;
  	char *ct_parent_path = NULL;
  
  	*match = 0;
  
  	if (strchr(ct->in_repo_path, '/') == NULL) {
  		*match = got_path_is_root_dir(path);
  		return NULL;
  	}
  
  	err = got_path_dirname(&ct_parent_path, ct->in_repo_path);
  	if (err)
  		return err;
  	*match = (strcmp(path, ct_parent_path) == 0);
  	free(ct_parent_path);
  	return err;
  }
  
  static mode_t
  get_ct_file_mode(struct got_commitable *ct)
  {
  	if (S_ISLNK(ct->mode))
  		return S_IFLNK;
  
  	return S_IFREG | (ct->mode & ((S_IRWXU | S_IRWXG | S_IRWXO)));
  }
  
  static const struct got_error *
  alloc_modified_blob_tree_entry(struct got_tree_entry **new_te,
      struct got_tree_entry *te, struct got_commitable *ct)
  {
  	const struct got_error *err = NULL;
  
  	*new_te = NULL;
  
  	err = got_object_tree_entry_dup(new_te, te);
  	if (err)
  		goto done;
  
  	(*new_te)->mode = get_ct_file_mode(ct);
  
  	if (ct->staged_status == GOT_STATUS_MODIFY)
  		memcpy(&(*new_te)->id, ct->staged_blob_id,
  		    sizeof((*new_te)->id));
  	else
  		memcpy(&(*new_te)->id, ct->blob_id, sizeof((*new_te)->id));
  done:
  	if (err && *new_te) {
  		free(*new_te);
  		*new_te = NULL;
  	}
  	return err;
  }
  
  static const struct got_error *
  alloc_added_blob_tree_entry(struct got_tree_entry **new_te,
      struct got_commitable *ct)
  {
  	const struct got_error *err = NULL;
  	char *ct_name = NULL;
  
  	 *new_te = NULL;
  
  	*new_te = calloc(1, sizeof(**new_te));
  	if (*new_te == NULL)
  		return got_error_from_errno("calloc");
  
  	err = got_path_basename(&ct_name, ct->path);
  	if (err)
  		goto done;
  	if (strlcpy((*new_te)->name, ct_name, sizeof((*new_te)->name)) >=
  	    sizeof((*new_te)->name)) {
  		err = got_error(GOT_ERR_NO_SPACE);
  		goto done;
  	}
  
  	(*new_te)->mode = get_ct_file_mode(ct);
  
  	if (ct->staged_status == GOT_STATUS_ADD)
  		memcpy(&(*new_te)->id, ct->staged_blob_id,
  		    sizeof((*new_te)->id));
  	else
  		memcpy(&(*new_te)->id, ct->blob_id, sizeof((*new_te)->id));
  done:
  	free(ct_name);
  	if (err && *new_te) {
  		free(*new_te);
  		*new_te = NULL;
  	}
  	return err;
  }
  
  static const struct got_error *
  insert_tree_entry(struct got_tree_entry *new_te,
      struct got_pathlist_head *paths)
  {
  	const struct got_error *err = NULL;
  	struct got_pathlist_entry *new_pe;
  
  	err = got_pathlist_insert(&new_pe, paths, new_te->name, new_te);
  	if (err)
  		return err;
  	if (new_pe == NULL)
  		return got_error(GOT_ERR_TREE_DUP_ENTRY);
  	return NULL;
  }
  
  static const struct got_error *
  report_ct_status(struct got_commitable *ct,
      got_worktree_status_cb status_cb, void *status_arg)
  {
  	const char *ct_path = ct->path;
  	unsigned char status;
  
  	if (status_cb == NULL) /* no commit progress output desired */
  		return NULL;
  
  	while (ct_path[0] == '/')
  		ct_path++;
  
  	if (ct->staged_status != GOT_STATUS_NO_CHANGE)
  		status = ct->staged_status;
  	else
  		status = ct->status;
  
  	return (*status_cb)(status_arg, status, GOT_STATUS_NO_CHANGE,
  	    ct_path, ct->blob_id, NULL, NULL, -1, NULL);
  }
  
  static const struct got_error *
  match_modified_subtree(int *modified, struct got_tree_entry *te,
      const char *base_tree_path, struct got_pathlist_head *commitable_paths)
  {
  	const struct got_error *err = NULL;
  	struct got_pathlist_entry *pe;
  	char *te_path;
  
  	*modified = 0;
  
  	if (asprintf(&te_path, "%s%s%s", base_tree_path,
  	    got_path_is_root_dir(base_tree_path) ? "" : "/",
  	    te->name) == -1)
  		return got_error_from_errno("asprintf");
  
  	TAILQ_FOREACH(pe, commitable_paths, entry) {
  		struct got_commitable *ct = pe->data;
  		*modified = got_path_is_child(ct->in_repo_path, te_path,
  		    strlen(te_path));
  		if (*modified)
  			break;
  	}
  
  	free(te_path);
  	return err;
  }
  
  static const struct got_error *
  match_deleted_or_modified_ct(struct got_commitable **ctp,
      struct got_tree_entry *te, const char *base_tree_path,
      struct got_pathlist_head *commitable_paths)
  {
  	const struct got_error *err = NULL;
  	struct got_pathlist_entry *pe;
  
  	*ctp = NULL;
  
  	TAILQ_FOREACH(pe, commitable_paths, entry) {
  		struct got_commitable *ct = pe->data;
  		char *ct_name = NULL;
  		int path_matches;
  
  		if (ct->staged_status == GOT_STATUS_NO_CHANGE) {
  			if (ct->status != GOT_STATUS_MODIFY &&
  			    ct->status != GOT_STATUS_MODE_CHANGE &&
  			    ct->status != GOT_STATUS_DELETE)
  				continue;
  		} else {
  			if (ct->staged_status != GOT_STATUS_MODIFY &&
  			    ct->staged_status != GOT_STATUS_DELETE)
  				continue;
  		}
  
  		if (got_object_id_cmp(ct->base_blob_id, &te->id) != 0)
  			continue;
  
  		err = match_ct_parent_path(&path_matches, ct, base_tree_path);
  		if (err)
  			return err;
  		if (!path_matches)
  			continue;
  
  		err = got_path_basename(&ct_name, pe->path);
  		if (err)
  			return err;
  
  		if (strcmp(te->name, ct_name) != 0) {
  			free(ct_name);
  			continue;
  		}
  		free(ct_name);
  
  		*ctp = ct;
  		break;
  	}
  
  	return err;
  }
  
  static const struct got_error *
  make_subtree_for_added_blob(struct got_tree_entry **new_tep,
      const char *child_path, const char *path_base_tree,
      struct got_pathlist_head *commitable_paths,
      got_worktree_status_cb status_cb, void *status_arg,
      struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	struct got_tree_entry *new_te;
  	char *subtree_path;
  	struct got_object_id *id = NULL;
  	int nentries;
  
  	*new_tep = NULL;
  
  	if (asprintf(&subtree_path, "%s%s%s", path_base_tree,
  	    got_path_is_root_dir(path_base_tree) ? "" : "/",
  	    child_path) == -1)
  		return got_error_from_errno("asprintf");
  
  	new_te = calloc(1, sizeof(*new_te));
  	if (new_te == NULL)
  		return got_error_from_errno("calloc");
  	new_te->mode = S_IFDIR;
  
  	if (strlcpy(new_te->name, child_path, sizeof(new_te->name)) >=
  	    sizeof(new_te->name)) {
  		err = got_error(GOT_ERR_NO_SPACE);
  		goto done;
  	}
  	err = write_tree(&id, &nentries, NULL, subtree_path,
  	    commitable_paths, status_cb, status_arg, repo);
  	if (err) {
  		free(new_te);
  		goto done;
  	}
  	memcpy(&new_te->id, id, sizeof(new_te->id));
  done:
  	free(id);
  	free(subtree_path);
  	if (err == NULL)
  		*new_tep = new_te;
  	return err;
  }
  
  static const struct got_error *
  write_tree(struct got_object_id **new_tree_id, int *nentries,
      struct got_tree_object *base_tree, const char *path_base_tree,
      struct got_pathlist_head *commitable_paths,
      got_worktree_status_cb status_cb, void *status_arg,
      struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	struct got_pathlist_head paths;
  	struct got_tree_entry *te, *new_te = NULL;
  	struct got_pathlist_entry *pe;
  
  	TAILQ_INIT(&paths);
  	*nentries = 0;
  
  	/* Insert, and recurse into, newly added entries first. */
  	TAILQ_FOREACH(pe, commitable_paths, entry) {
  		struct got_commitable *ct = pe->data;
  		char *child_path = NULL, *slash;
  
  		if ((ct->status != GOT_STATUS_ADD &&
  		    ct->staged_status != GOT_STATUS_ADD) ||
  		    (ct->flags & GOT_COMMITABLE_ADDED))
  			continue;
  
  		if (!got_path_is_child(ct->in_repo_path, path_base_tree,
  		    strlen(path_base_tree)))
  			continue;
  
  		err = got_path_skip_common_ancestor(&child_path, path_base_tree,
  		    ct->in_repo_path);
  		if (err)
  			goto done;
  
  		slash = strchr(child_path, '/');
  		if (slash == NULL) {
  			err = alloc_added_blob_tree_entry(&new_te, ct);
  			if (err)
  				goto done;
  			err = report_ct_status(ct, status_cb, status_arg);
  			if (err)
  				goto done;
  			ct->flags |= GOT_COMMITABLE_ADDED;
  			err = insert_tree_entry(new_te, &paths);
  			if (err)
  				goto done;
  			(*nentries)++;
  		} else {
  			*slash = '\0'; /* trim trailing path components */
  			if (base_tree == NULL ||
  			    got_object_tree_find_entry(base_tree, child_path)
  			    == NULL) {
  				err = make_subtree_for_added_blob(&new_te,
  				    child_path, path_base_tree,
  				    commitable_paths, status_cb, status_arg,
  				    repo);
  				if (err)
  					goto done;
  				err = insert_tree_entry(new_te, &paths);
  				if (err)
  					goto done;
  				(*nentries)++;
  			}
  		}
  	}
  
  	if (base_tree) {
  		int i, nbase_entries;
  		/* Handle modified and deleted entries. */
  		nbase_entries = got_object_tree_get_nentries(base_tree);
  		for (i = 0; i < nbase_entries; i++) {
  			struct got_commitable *ct = NULL;
  
  			te = got_object_tree_get_entry(base_tree, i);
  			if (got_object_tree_entry_is_submodule(te)) {
  				/* Entry is a submodule; just copy it. */
  				err = got_object_tree_entry_dup(&new_te, te);
  				if (err)
  					goto done;
  				err = insert_tree_entry(new_te, &paths);
  				if (err)
  					goto done;
  				(*nentries)++;
  				continue;
  			}
  
  			if (S_ISDIR(te->mode)) {
  				int modified;
  				err = got_object_tree_entry_dup(&new_te, te);
  				if (err)
  					goto done;
  				err = match_modified_subtree(&modified, te,
  				    path_base_tree, commitable_paths);
  				if (err)
  					goto done;
  				/* Avoid recursion into unmodified subtrees. */
  				if (modified) {
  					struct got_object_id *new_id;
  					int nsubentries;
  					err = write_subtree(&new_id,
  					    &nsubentries, te,
  					    path_base_tree, commitable_paths,
  					    status_cb, status_arg, repo);
  					if (err)
  						goto done;
  					if (nsubentries == 0) {
  						/* All entries were deleted. */
  						free(new_id);
  						continue;
  					}
  					memcpy(&new_te->id, new_id,
  					    sizeof(new_te->id));
  					free(new_id);
  				}
  				err = insert_tree_entry(new_te, &paths);
  				if (err)
  					goto done;
  				(*nentries)++;
  				continue;
  			}
  
  			err = match_deleted_or_modified_ct(&ct, te,
  			    path_base_tree, commitable_paths);
  			if (err)
  				goto done;
  			if (ct) {
  				/* NB: Deleted entries get dropped here. */
  				if (ct->status == GOT_STATUS_MODIFY ||
  				    ct->status == GOT_STATUS_MODE_CHANGE ||
  				    ct->staged_status == GOT_STATUS_MODIFY) {
  					err = alloc_modified_blob_tree_entry(
  					    &new_te, te, ct);
  					if (err)
  						goto done;
  					err = insert_tree_entry(new_te, &paths);
  					if (err)
  						goto done;
  					(*nentries)++;
  				}
  				err = report_ct_status(ct, status_cb,
  				    status_arg);
  				if (err)
  					goto done;
  			} else {
  				/* Entry is unchanged; just copy it. */
  				err = got_object_tree_entry_dup(&new_te, te);
  				if (err)
  					goto done;
  				err = insert_tree_entry(new_te, &paths);
  				if (err)
  					goto done;
  				(*nentries)++;
  			}
  		}
  	}
  
  	/* Write new list of entries; deleted entries have been dropped. */
  	err = got_object_tree_create(new_tree_id, &paths, *nentries, repo);
  done:
  	got_pathlist_free(&paths);
  	return err;
  }
  
  static const struct got_error *
  update_fileindex_after_commit(struct got_worktree *worktree,
      struct got_pathlist_head *commitable_paths,
      struct got_object_id *new_base_commit_id,
      struct got_fileindex *fileindex, int have_staged_files)
  {
  	const struct got_error *err = NULL;
  	struct got_pathlist_entry *pe;
  	char *relpath = NULL;
  
  	TAILQ_FOREACH(pe, commitable_paths, entry) {
  		struct got_fileindex_entry *ie;
  		struct got_commitable *ct = pe->data;
  
  		ie = got_fileindex_entry_get(fileindex, pe->path, pe->path_len);
  
  		err = got_path_skip_common_ancestor(&relpath,
  		    worktree->root_path, ct->ondisk_path);
  		if (err)
  			goto done;
  
  		if (ie) {
  			if (ct->status == GOT_STATUS_DELETE ||
  			    ct->staged_status == GOT_STATUS_DELETE) {
  				got_fileindex_entry_remove(fileindex, ie);
  			} else if (ct->staged_status == GOT_STATUS_ADD ||
  			    ct->staged_status == GOT_STATUS_MODIFY) {
  				got_fileindex_entry_stage_set(ie,
  				    GOT_FILEIDX_STAGE_NONE);
  				got_fileindex_entry_staged_filetype_set(ie, 0);
  
  				err = got_fileindex_entry_update(ie,
  				    worktree->root_fd, relpath,
  				    ct->staged_blob_id->sha1,
  				    new_base_commit_id->sha1,
  				    !have_staged_files);
  			} else
  				err = got_fileindex_entry_update(ie,
  				    worktree->root_fd, relpath,
  				    ct->blob_id->sha1,
  				    new_base_commit_id->sha1,
  				    !have_staged_files);
  		} else {
  			err = got_fileindex_entry_alloc(&ie, pe->path);
  			if (err)
  				goto done;
  			err = got_fileindex_entry_update(ie,
  			    worktree->root_fd, relpath, ct->blob_id->sha1,
  			    new_base_commit_id->sha1, 1);
  			if (err) {
  				got_fileindex_entry_free(ie);
  				goto done;
  			}
  			err = got_fileindex_entry_add(fileindex, ie);
  			if (err) {
  				got_fileindex_entry_free(ie);
  				goto done;
  			}
  		}
  		free(relpath);
  		relpath = NULL;
  	}
  done:
  	free(relpath);
  	return err;
  }
  
  
  static const struct got_error *
  check_out_of_date(const char *in_repo_path, unsigned char status,
      unsigned char staged_status, struct got_object_id *base_blob_id,
      struct got_object_id *base_commit_id,
      struct got_object_id *head_commit_id, struct got_repository *repo,
      int ood_errcode)
  {
  	const struct got_error *err = NULL;
  	struct got_commit_object *commit = NULL;
  	struct got_object_id *id = NULL;
  
  	if (status != GOT_STATUS_ADD && staged_status != GOT_STATUS_ADD) {
  		/* Trivial case: base commit == head commit */
  		if (got_object_id_cmp(base_commit_id, head_commit_id) == 0)
  			return NULL;
  		/*
  		 * Ensure file content which local changes were based
  		 * on matches file content in the branch head.
  		 */
  		err = got_object_open_as_commit(&commit, repo, head_commit_id);
  		if (err)
  			goto done;
  		err = got_object_id_by_path(&id, repo, commit, in_repo_path);
  		if (err) {
  			if (err->code == GOT_ERR_NO_TREE_ENTRY)
  				err = got_error(ood_errcode);
  			goto done;
  		} else if (got_object_id_cmp(id, base_blob_id) != 0)
  			err = got_error(ood_errcode);
  	} else {
  		/* Require that added files don't exist in the branch head. */
  		err = got_object_open_as_commit(&commit, repo, head_commit_id);
  		if (err)
  			goto done;
  		err = got_object_id_by_path(&id, repo, commit, in_repo_path);
  		if (err && err->code != GOT_ERR_NO_TREE_ENTRY)
  			goto done;
  		err = id ? got_error(ood_errcode) : NULL;
  	}
  done:
  	free(id);
  	if (commit)
  		got_object_commit_close(commit);
  	return err;
  }
  
  const struct got_error *
  commit_worktree(struct got_object_id **new_commit_id,
      struct got_pathlist_head *commitable_paths,
      struct got_object_id *head_commit_id,
      struct got_object_id *parent_id2,
      struct got_worktree *worktree,
      const char *author, const char *committer,
      got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
      got_worktree_status_cb status_cb, void *status_arg,
      struct got_repository *repo)
  {
  	const struct got_error *err = NULL, *unlockerr = NULL;
  	struct got_pathlist_entry *pe;
  	const char *head_ref_name = NULL;
  	struct got_commit_object *head_commit = NULL;
  	struct got_reference *head_ref2 = NULL;
  	struct got_object_id *head_commit_id2 = NULL;
  	struct got_tree_object *head_tree = NULL;
  	struct got_object_id *new_tree_id = NULL;
  	int nentries, nparents = 0;
  	struct got_object_id_queue parent_ids;
  	struct got_object_qid *pid = NULL;
  	char *logmsg = NULL;
  
  	*new_commit_id = NULL;
  
  	STAILQ_INIT(&parent_ids);
  
  	err = got_object_open_as_commit(&head_commit, repo, head_commit_id);
  	if (err)
  		goto done;
  
  	err = got_object_open_as_tree(&head_tree, repo, head_commit->tree_id);
  	if (err)
  		goto done;
  
  	if (commit_msg_cb != NULL) {
  		err = commit_msg_cb(commitable_paths, &logmsg, commit_arg);
  		if (err)
  			goto done;
  	}
  
  	if (logmsg == NULL || strlen(logmsg) == 0) {
  		err = got_error(GOT_ERR_COMMIT_MSG_EMPTY);
  		goto done;
  	}
  
  	/* Create blobs from added and modified files and record their IDs. */
  	TAILQ_FOREACH(pe, commitable_paths, entry) {
  		struct got_commitable *ct = pe->data;
  		char *ondisk_path;
  
  		/* Blobs for staged files already exist. */
  		if (ct->staged_status == GOT_STATUS_ADD ||
  		    ct->staged_status == GOT_STATUS_MODIFY)
  			continue;
  
  		if (ct->status != GOT_STATUS_ADD &&
  		    ct->status != GOT_STATUS_MODIFY &&
  		    ct->status != GOT_STATUS_MODE_CHANGE)
  			continue;
  
  		if (asprintf(&ondisk_path, "%s/%s",
  		    worktree->root_path, pe->path) == -1) {
  			err = got_error_from_errno("asprintf");
  			goto done;
  		}
  		err = got_object_blob_create(&ct->blob_id, ondisk_path, repo);
  		free(ondisk_path);
  		if (err)
  			goto done;
  	}
  
  	/* Recursively write new tree objects. */
  	err = write_tree(&new_tree_id, &nentries, head_tree, "/",
  	    commitable_paths, status_cb, status_arg, repo);
  	if (err)
  		goto done;
  
  	err = got_object_qid_alloc(&pid, worktree->base_commit_id);
  	if (err)
  		goto done;
  	STAILQ_INSERT_TAIL(&parent_ids, pid, entry);
  	nparents++;
  	if (parent_id2) {
  		err = got_object_qid_alloc(&pid, parent_id2);
  		if (err)
  			goto done;
  		STAILQ_INSERT_TAIL(&parent_ids, pid, entry);
  		nparents++;
  	}
  	err = got_object_commit_create(new_commit_id, new_tree_id, &parent_ids,
  	    nparents, author, time(NULL), committer, time(NULL), logmsg, repo);
  	if (logmsg != NULL)
  		free(logmsg);
  	if (err)
  		goto done;
  
  	/* Check if a concurrent commit to our branch has occurred. */
  	head_ref_name = got_worktree_get_head_ref_name(worktree);
  	if (head_ref_name == NULL) {
  		err = got_error_from_errno("got_worktree_get_head_ref_name");
  		goto done;
  	}
  	/* Lock the reference here to prevent concurrent modification. */
  	err = got_ref_open(&head_ref2, repo, head_ref_name, 1);
  	if (err)
  		goto done;
  	err = got_ref_resolve(&head_commit_id2, repo, head_ref2);
  	if (err)
  		goto done;
  	if (got_object_id_cmp(head_commit_id, head_commit_id2) != 0) {
  		err = got_error(GOT_ERR_COMMIT_HEAD_CHANGED);
  		goto done;
  	}
  	/* Update branch head in repository. */
  	err = got_ref_change_ref(head_ref2, *new_commit_id);
  	if (err)
  		goto done;
  	err = got_ref_write(head_ref2, repo);
  	if (err)
  		goto done;
  
  	err = got_worktree_set_base_commit_id(worktree, repo, *new_commit_id);
  	if (err)
  		goto done;
  
  	err = ref_base_commit(worktree, repo);
  	if (err)
  		goto done;
  done:
  	got_object_id_queue_free(&parent_ids);
  	if (head_tree)
  		got_object_tree_close(head_tree);
  	if (head_commit)
  		got_object_commit_close(head_commit);
  	free(head_commit_id2);
  	if (head_ref2) {
  		unlockerr = got_ref_unlock(head_ref2);
  		if (unlockerr && err == NULL)
  			err = unlockerr;
  		got_ref_close(head_ref2);
  	}
  	return err;
  }
  
  static const struct got_error *
  check_path_is_commitable(const char *path,
      struct got_pathlist_head *commitable_paths)
  {
  	struct got_pathlist_entry *cpe = NULL;
  	size_t path_len = strlen(path);
  
  	TAILQ_FOREACH(cpe, commitable_paths, entry) {
  		struct got_commitable *ct = cpe->data;
  		const char *ct_path = ct->path;
  
  		while (ct_path[0] == '/')
  			ct_path++;
  
  		if (strcmp(path, ct_path) == 0 ||
  		    got_path_is_child(ct_path, path, path_len))
  			break;
  	}
  
  	if (cpe == NULL)
  		return got_error_path(path, GOT_ERR_BAD_PATH);
  
  	return NULL;
  }
  
  static const struct got_error *
  check_staged_file(void *arg, struct got_fileindex_entry *ie)
  {
  	int *have_staged_files = arg;
  
  	if (got_fileindex_entry_stage_get(ie) != GOT_FILEIDX_STAGE_NONE) {
  		*have_staged_files = 1;
  		return got_error(GOT_ERR_CANCELLED);
  	}
  
  	return NULL;
  }
  
  static const struct got_error *
  check_non_staged_files(struct got_fileindex *fileindex,
      struct got_pathlist_head *paths)
  {
  	struct got_pathlist_entry *pe;
  	struct got_fileindex_entry *ie;
  
  	TAILQ_FOREACH(pe, paths, entry) {
  		if (pe->path[0] == '\0')
  			continue;
  		ie = got_fileindex_entry_get(fileindex, pe->path, pe->path_len);
  		if (ie == NULL)
  			return got_error_path(pe->path, GOT_ERR_BAD_PATH);
  		if (got_fileindex_entry_stage_get(ie) == GOT_FILEIDX_STAGE_NONE)
  			return got_error_path(pe->path,
  			    GOT_ERR_FILE_NOT_STAGED);
  	}
  
  	return NULL;
  }
  
  const struct got_error *
  got_worktree_commit(struct got_object_id **new_commit_id,
      struct got_worktree *worktree, struct got_pathlist_head *paths,
      const char *author, const char *committer, int allow_bad_symlinks,
      got_worktree_commit_msg_cb commit_msg_cb, void *commit_arg,
      got_worktree_status_cb status_cb, void *status_arg,
      struct got_repository *repo)
  {
  	const struct got_error *err = NULL, *unlockerr = NULL, *sync_err;
  	struct got_fileindex *fileindex = NULL;
  	char *fileindex_path = NULL;
  	struct got_pathlist_head commitable_paths;
  	struct collect_commitables_arg cc_arg;
  	struct got_pathlist_entry *pe;
  	struct got_reference *head_ref = NULL;
  	struct got_object_id *head_commit_id = NULL;
  	int have_staged_files = 0;
  
  	*new_commit_id = NULL;
  
  	TAILQ_INIT(&commitable_paths);
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		goto done;
  
  	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
  	if (err)
  		goto done;
  
  	err = got_ref_resolve(&head_commit_id, repo, head_ref);
  	if (err)
  		goto done;
  
  	err = open_fileindex(&fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	err = got_fileindex_for_each_entry_safe(fileindex, check_staged_file,
  	    &have_staged_files);
  	if (err && err->code != GOT_ERR_CANCELLED)
  		goto done;
  	if (have_staged_files) {
  		err = check_non_staged_files(fileindex, paths);
  		if (err)
  			goto done;
  	}
  
  	cc_arg.commitable_paths = &commitable_paths;
  	cc_arg.worktree = worktree;
  	cc_arg.fileindex = fileindex;
  	cc_arg.repo = repo;
  	cc_arg.have_staged_files = have_staged_files;
  	cc_arg.allow_bad_symlinks = allow_bad_symlinks;
  	TAILQ_FOREACH(pe, paths, entry) {
  		err = worktree_status(worktree, pe->path, fileindex, repo,
  		    collect_commitables, &cc_arg, NULL, NULL, 1, 0);
  		if (err)
  			goto done;
  	}
  
  	if (TAILQ_EMPTY(&commitable_paths)) {
  		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
  		goto done;
  	}
  
  	TAILQ_FOREACH(pe, paths, entry) {
  		err = check_path_is_commitable(pe->path, &commitable_paths);
  		if (err)
  			goto done;
  	}
  
  	TAILQ_FOREACH(pe, &commitable_paths, entry) {
  		struct got_commitable *ct = pe->data;
  		const char *ct_path = ct->in_repo_path;
  
  		while (ct_path[0] == '/')
  			ct_path++;
  		err = check_out_of_date(ct_path, ct->status,
  		    ct->staged_status, ct->base_blob_id, ct->base_commit_id,
  		    head_commit_id, repo, GOT_ERR_COMMIT_OUT_OF_DATE);
  		if (err)
  			goto done;
  
  	}
  
  	err = commit_worktree(new_commit_id, &commitable_paths,
  	    head_commit_id, NULL, worktree, author, committer,
  	    commit_msg_cb, commit_arg, status_cb, status_arg, repo);
  	if (err)
  		goto done;
  
  	err = update_fileindex_after_commit(worktree, &commitable_paths,
  	    *new_commit_id, fileindex, have_staged_files);
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	free(fileindex_path);
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	TAILQ_FOREACH(pe, &commitable_paths, entry) {
  		struct got_commitable *ct = pe->data;
  		free_commitable(ct);
  	}
  	got_pathlist_free(&commitable_paths);
  	return err;
  }
  
  const char *
  got_commitable_get_path(struct got_commitable *ct)
  {
  	return ct->path;
  }
  
  unsigned int
  got_commitable_get_status(struct got_commitable *ct)
  {
  	return ct->status;
  }
  
  struct check_rebase_ok_arg {
  	struct got_worktree *worktree;
  	struct got_repository *repo;
  };
  
  static const struct got_error *
  check_rebase_ok(void *arg, struct got_fileindex_entry *ie)
  {
  	const struct got_error *err = NULL;
  	struct check_rebase_ok_arg *a = arg;
  	unsigned char status;
  	struct stat sb;
  	char *ondisk_path;
  
  	/* Reject rebase of a work tree with mixed base commits. */
  	if (memcmp(ie->commit_sha1, a->worktree->base_commit_id->sha1,
  	    SHA1_DIGEST_LENGTH))
  		return got_error(GOT_ERR_MIXED_COMMITS);
  
  	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, ie->path)
  	    == -1)
  		return got_error_from_errno("asprintf");
  
  	/* Reject rebase of a work tree with modified or staged files. */
  	err = get_file_status(&status, &sb, ie, ondisk_path, -1, NULL, a->repo);
  	free(ondisk_path);
  	if (err)
  		return err;
  
  	if (status != GOT_STATUS_NO_CHANGE)
  		return got_error(GOT_ERR_MODIFIED);
  	if (get_staged_status(ie) != GOT_STATUS_NO_CHANGE)
  		return got_error_path(ie->path, GOT_ERR_FILE_STAGED);
  
  	return NULL;
  }
  
  const struct got_error *
  got_worktree_rebase_prepare(struct got_reference **new_base_branch_ref,
      struct got_reference **tmp_branch, struct got_fileindex **fileindex,
      struct got_worktree *worktree, struct got_reference *branch,
      struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
  	char *branch_ref_name = NULL;
  	char *fileindex_path = NULL;
  	struct check_rebase_ok_arg ok_arg;
  	struct got_reference *wt_branch = NULL, *branch_ref = NULL;
  	struct got_object_id *wt_branch_tip = NULL;
  
  	*new_base_branch_ref = NULL;
  	*tmp_branch = NULL;
  	*fileindex = NULL;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = open_fileindex(fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	ok_arg.worktree = worktree;
  	ok_arg.repo = repo;
  	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
  	    &ok_arg);
  	if (err)
  		goto done;
  
  	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
  	if (err)
  		goto done;
  
  	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
  	if (err)
  		goto done;
  
  	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
  	if (err)
  		goto done;
  
  	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
  	    0);
  	if (err)
  		goto done;
  
  	err = got_ref_resolve(&wt_branch_tip, repo, wt_branch);
  	if (err)
  		goto done;
  	if (got_object_id_cmp(worktree->base_commit_id, wt_branch_tip) != 0) {
  		err = got_error(GOT_ERR_REBASE_OUT_OF_DATE);
  		goto done;
  	}
  
  	err = got_ref_alloc_symref(new_base_branch_ref,
  	    new_base_branch_ref_name, wt_branch);
  	if (err)
  		goto done;
  	err = got_ref_write(*new_base_branch_ref, repo);
  	if (err)
  		goto done;
  
  	/* TODO Lock original branch's ref while rebasing? */
  
  	err = got_ref_alloc_symref(&branch_ref, branch_ref_name, branch);
  	if (err)
  		goto done;
  
  	err = got_ref_write(branch_ref, repo);
  	if (err)
  		goto done;
  
  	err = got_ref_alloc(tmp_branch, tmp_branch_name,
  	    worktree->base_commit_id);
  	if (err)
  		goto done;
  	err = got_ref_write(*tmp_branch, repo);
  	if (err)
  		goto done;
  
  	err = got_worktree_set_head_ref(worktree, *tmp_branch);
  	if (err)
  		goto done;
  done:
  	free(fileindex_path);
  	free(tmp_branch_name);
  	free(new_base_branch_ref_name);
  	free(branch_ref_name);
  	if (branch_ref)
  		got_ref_close(branch_ref);
  	if (wt_branch)
  		got_ref_close(wt_branch);
  	free(wt_branch_tip);
  	if (err) {
  		if (*new_base_branch_ref) {
  			got_ref_close(*new_base_branch_ref);
  			*new_base_branch_ref = NULL;
  		}
  		if (*tmp_branch) {
  			got_ref_close(*tmp_branch);
  			*tmp_branch = NULL;
  		}
  		if (*fileindex) {
  			got_fileindex_free(*fileindex);
  			*fileindex = NULL;
  		}
  		lock_worktree(worktree, LOCK_SH);
  	}
  	return err;
  }
  
  const struct got_error *
  got_worktree_rebase_continue(struct got_object_id **commit_id,
      struct got_reference **new_base_branch, struct got_reference **tmp_branch,
      struct got_reference **branch, struct got_fileindex **fileindex,
      struct got_worktree *worktree, struct got_repository *repo)
  {
  	const struct got_error *err;
  	char *commit_ref_name = NULL, *new_base_branch_ref_name = NULL;
  	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
  	struct got_reference *commit_ref = NULL, *branch_ref = NULL;
  	char *fileindex_path = NULL;
  	int have_staged_files = 0;
  
  	*commit_id = NULL;
  	*new_base_branch = NULL;
  	*tmp_branch = NULL;
  	*branch = NULL;
  	*fileindex = NULL;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = open_fileindex(fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	err = got_fileindex_for_each_entry_safe(*fileindex, check_staged_file,
  	    &have_staged_files);
  	if (err && err->code != GOT_ERR_CANCELLED)
  		goto done;
  	if (have_staged_files) {
  		err = got_error(GOT_ERR_STAGED_PATHS);
  		goto done;
  	}
  
  	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
  	if (err)
  		goto done;
  
  	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
  	if (err)
  		goto done;
  
  	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
  	if (err)
  		goto done;
  
  	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
  	if (err)
  		goto done;
  
  	err = got_ref_open(&branch_ref, repo, branch_ref_name, 0);
  	if (err)
  		goto done;
  
  	err = got_ref_open(branch, repo,
  	    got_ref_get_symref_target(branch_ref), 0);
  	if (err)
  		goto done;
  
  	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
  	if (err)
  		goto done;
  
  	err = got_ref_resolve(commit_id, repo, commit_ref);
  	if (err)
  		goto done;
  
  	err = got_ref_open(new_base_branch, repo,
  	    new_base_branch_ref_name, 0);
  	if (err)
  		goto done;
  
  	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
  	if (err)
  		goto done;
  done:
  	free(commit_ref_name);
  	free(branch_ref_name);
  	free(fileindex_path);
  	if (commit_ref)
  		got_ref_close(commit_ref);
  	if (branch_ref)
  		got_ref_close(branch_ref);
  	if (err) {
  		free(*commit_id);
  		*commit_id = NULL;
  		if (*tmp_branch) {
  			got_ref_close(*tmp_branch);
  			*tmp_branch = NULL;
  		}
  		if (*new_base_branch) {
  			got_ref_close(*new_base_branch);
  			*new_base_branch = NULL;
  		}
  		if (*branch) {
  			got_ref_close(*branch);
  			*branch = NULL;
  		}
  		if (*fileindex) {
  			got_fileindex_free(*fileindex);
  			*fileindex = NULL;
  		}
  		lock_worktree(worktree, LOCK_SH);
  	}
  	return err;
  }
  
  const struct got_error *
  got_worktree_rebase_in_progress(int *in_progress, struct got_worktree *worktree)
  {
  	const struct got_error *err;
  	char *tmp_branch_name = NULL;
  
  	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
  	if (err)
  		return err;
  
  	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
  	free(tmp_branch_name);
  	return NULL;
  }
  
  static const struct got_error *
  collect_rebase_commit_msg(struct got_pathlist_head *commitable_paths,
      char **logmsg, void *arg)
  {
  	*logmsg = arg;
  	return NULL;
  }
  
  static const struct got_error *
  rebase_status(void *arg, unsigned char status, unsigned char staged_status,
      const char *path, struct got_object_id *blob_id,
      struct got_object_id *staged_blob_id, struct got_object_id *commit_id,
      int dirfd, const char *de_name)
  {
  	return NULL;
  }
  
  struct collect_merged_paths_arg {
  	got_worktree_checkout_cb progress_cb;
  	void *progress_arg;
  	struct got_pathlist_head *merged_paths;
  };
  
  static const struct got_error *
  collect_merged_paths(void *arg, unsigned char status, const char *path)
  {
  	const struct got_error *err;
  	struct collect_merged_paths_arg *a = arg;
  	char *p;
  	struct got_pathlist_entry *new;
  
  	err = (*a->progress_cb)(a->progress_arg, status, path);
  	if (err)
  		return err;
  
  	if (status != GOT_STATUS_MERGE &&
  	    status != GOT_STATUS_ADD &&
  	    status != GOT_STATUS_DELETE &&
  	    status != GOT_STATUS_CONFLICT)
  		return NULL;
  
  	p = strdup(path);
  	if (p == NULL)
  		return got_error_from_errno("strdup");
  
  	err = got_pathlist_insert(&new, a->merged_paths, p, NULL);
  	if (err || new == NULL)
  		free(p);
  	return err;
  }
  
  void
  got_worktree_rebase_pathlist_free(struct got_pathlist_head *merged_paths)
  {
  	struct got_pathlist_entry *pe;
  
  	TAILQ_FOREACH(pe, merged_paths, entry)
  		free((char *)pe->path);
  
  	got_pathlist_free(merged_paths);
  }
  
  static const struct got_error *
  store_commit_id(const char *commit_ref_name, struct got_object_id *commit_id,
      int is_rebase, struct got_repository *repo)
  {
  	const struct got_error *err;
  	struct got_reference *commit_ref = NULL;
  
  	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
  	if (err) {
  		if (err->code != GOT_ERR_NOT_REF)
  			goto done;
  		err = got_ref_alloc(&commit_ref, commit_ref_name, commit_id);
  		if (err)
  			goto done;
  		err = got_ref_write(commit_ref, repo);
  		if (err)
  			goto done;
  	} else if (is_rebase) {
  		struct got_object_id *stored_id;
  		int cmp;
  
  		err = got_ref_resolve(&stored_id, repo, commit_ref);
  		if (err)
  			goto done;
  		cmp = got_object_id_cmp(commit_id, stored_id);
  		free(stored_id);
  		if (cmp != 0) {
  			err = got_error(GOT_ERR_REBASE_COMMITID);
  			goto done;
  		}
  	}
  done:
  	if (commit_ref)
  		got_ref_close(commit_ref);
  	return err;
  }
  
  static const struct got_error *
  rebase_merge_files(struct got_pathlist_head *merged_paths,
      const char *commit_ref_name, struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_object_id *parent_commit_id,
      struct got_object_id *commit_id, struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg,
      got_cancel_cb cancel_cb, void *cancel_arg)
  {
  	const struct got_error *err;
  	struct got_reference *commit_ref = NULL;
  	struct collect_merged_paths_arg cmp_arg;
  	char *fileindex_path;
  
  	/* Work tree is locked/unlocked during rebase preparation/teardown. */
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		return err;
  
  	cmp_arg.progress_cb = progress_cb;
  	cmp_arg.progress_arg = progress_arg;
  	cmp_arg.merged_paths = merged_paths;
  	err = merge_files(worktree, fileindex, fileindex_path,
  	    parent_commit_id, commit_id, repo, collect_merged_paths,
  	    &cmp_arg, cancel_cb, cancel_arg);
  	if (commit_ref)
  		got_ref_close(commit_ref);
  	return err;
  }
  
  const struct got_error *
  got_worktree_rebase_merge_files(struct got_pathlist_head *merged_paths,
      struct got_worktree *worktree, struct got_fileindex *fileindex,
      struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
      struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg,
      got_cancel_cb cancel_cb, void *cancel_arg)
  {
  	const struct got_error *err;
  	char *commit_ref_name;
  
  	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
  	if (err)
  		return err;
  
  	err = store_commit_id(commit_ref_name, commit_id, 1, repo);
  	if (err)
  		goto done;
  
  	err = rebase_merge_files(merged_paths, commit_ref_name, worktree,
  	    fileindex, parent_commit_id, commit_id, repo, progress_cb,
  	    progress_arg, cancel_cb, cancel_arg);
  done:
  	free(commit_ref_name);
  	return err;
  }
  
  const struct got_error *
  got_worktree_histedit_merge_files(struct got_pathlist_head *merged_paths,
      struct got_worktree *worktree, struct got_fileindex *fileindex,
      struct got_object_id *parent_commit_id, struct got_object_id *commit_id,
      struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg,
      got_cancel_cb cancel_cb, void *cancel_arg)
  {
  	const struct got_error *err;
  	char *commit_ref_name;
  
  	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
  	if (err)
  		return err;
  
  	err = store_commit_id(commit_ref_name, commit_id, 0, repo);
  	if (err)
  		goto done;
  
  	err = rebase_merge_files(merged_paths, commit_ref_name, worktree,
  	    fileindex, parent_commit_id, commit_id, repo, progress_cb,
  	    progress_arg, cancel_cb, cancel_arg);
  done:
  	free(commit_ref_name);
  	return err;
  }
  
  static const struct got_error *
  rebase_commit(struct got_object_id **new_commit_id,
      struct got_pathlist_head *merged_paths, struct got_reference *commit_ref,
      struct got_worktree *worktree, struct got_fileindex *fileindex,
      struct got_reference *tmp_branch, struct got_commit_object *orig_commit,
      const char *new_logmsg, struct got_repository *repo)
  {
  	const struct got_error *err, *sync_err;
  	struct got_pathlist_head commitable_paths;
  	struct collect_commitables_arg cc_arg;
  	char *fileindex_path = NULL;
  	struct got_reference *head_ref = NULL;
  	struct got_object_id *head_commit_id = NULL;
  	char *logmsg = NULL;
  
  	TAILQ_INIT(&commitable_paths);
  	*new_commit_id = NULL;
  
  	/* Work tree is locked/unlocked during rebase preparation/teardown. */
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		return err;
  
  	cc_arg.commitable_paths = &commitable_paths;
  	cc_arg.worktree = worktree;
  	cc_arg.repo = repo;
  	cc_arg.have_staged_files = 0;
  	/*
  	 * If possible get the status of individual files directly to
  	 * avoid crawling the entire work tree once per rebased commit.
  	 *
  	 * Ideally, merged_paths would contain a list of commitables
  	 * we could use so we could skip worktree_status() entirely.
  	 * However, we would then need carefully keep track of cumulative
  	 * effects of operations such as file additions and deletions
  	 * in 'got histedit -f' (folding multiple commits into one),
  	 * and this extra complexity is not really worth it.
  	 */
  	if (merged_paths) {
  		struct got_pathlist_entry *pe;
  		TAILQ_FOREACH(pe, merged_paths, entry) {
  			err = worktree_status(worktree, pe->path, fileindex,
  			    repo, collect_commitables, &cc_arg, NULL, NULL, 1,
  			    0);
  			if (err)
  				goto done;
  		}
  	} else {
  		err = worktree_status(worktree, "", fileindex, repo,
  		    collect_commitables, &cc_arg, NULL, NULL, 1, 0);
  		if (err)
  			goto done;
  	}
  
  	if (TAILQ_EMPTY(&commitable_paths)) {
  		/* No-op change; commit will be elided. */
  		err = got_ref_delete(commit_ref, repo);
  		if (err)
  			goto done;
  		err = got_error(GOT_ERR_COMMIT_NO_CHANGES);
  		goto done;
  	}
  
  	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
  	if (err)
  		goto done;
  
  	err = got_ref_resolve(&head_commit_id, repo, head_ref);
  	if (err)
  		goto done;
  
  	if (new_logmsg) {
  		logmsg = strdup(new_logmsg);
  		if (logmsg == NULL) {
  			err = got_error_from_errno("strdup");
  			goto done;
  		}
  	} else {
  		err = got_object_commit_get_logmsg(&logmsg, orig_commit);
  		if (err)
  			goto done;
  	}
  
  	/* NB: commit_worktree will call free(logmsg) */
  	err = commit_worktree(new_commit_id, &commitable_paths, head_commit_id,
  	    NULL, worktree, got_object_commit_get_author(orig_commit),
  	    got_object_commit_get_committer(orig_commit),
  	    collect_rebase_commit_msg, logmsg, rebase_status, NULL, repo);
  	if (err)
  		goto done;
  
  	err = got_ref_change_ref(tmp_branch, *new_commit_id);
  	if (err)
  		goto done;
  
  	err = got_ref_delete(commit_ref, repo);
  	if (err)
  		goto done;
  
  	err = update_fileindex_after_commit(worktree, &commitable_paths,
  	    *new_commit_id, fileindex, 0);
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	free(fileindex_path);
  	free(head_commit_id);
  	if (head_ref)
  		got_ref_close(head_ref);
  	if (err) {
  		free(*new_commit_id);
  		*new_commit_id = NULL;
  	}
  	return err;
  }
  
  const struct got_error *
  got_worktree_rebase_commit(struct got_object_id **new_commit_id,
      struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_reference *tmp_branch,
      struct got_commit_object *orig_commit,
      struct got_object_id *orig_commit_id, struct got_repository *repo)
  {
  	const struct got_error *err;
  	char *commit_ref_name;
  	struct got_reference *commit_ref = NULL;
  	struct got_object_id *commit_id = NULL;
  
  	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
  	if (err)
  		return err;
  
  	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
  	if (err)
  		goto done;
  	err = got_ref_resolve(&commit_id, repo, commit_ref);
  	if (err)
  		goto done;
  	if (got_object_id_cmp(commit_id, orig_commit_id) != 0) {
  		err = got_error(GOT_ERR_REBASE_COMMITID);
  		goto done;
  	}
  
  	err = rebase_commit(new_commit_id, merged_paths, commit_ref,
  	    worktree, fileindex, tmp_branch, orig_commit, NULL, repo);
  done:
  	if (commit_ref)
  		got_ref_close(commit_ref);
  	free(commit_ref_name);
  	free(commit_id);
  	return err;
  }
  
  const struct got_error *
  got_worktree_histedit_commit(struct got_object_id **new_commit_id,
      struct got_pathlist_head *merged_paths, struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_reference *tmp_branch,
      struct got_commit_object *orig_commit,
      struct got_object_id *orig_commit_id, const char *new_logmsg,
      struct got_repository *repo)
  {
  	const struct got_error *err;
  	char *commit_ref_name;
  	struct got_reference *commit_ref = NULL;
  
  	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
  	if (err)
  		return err;
  
  	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
  	if (err)
  		goto done;
  
  	err = rebase_commit(new_commit_id, merged_paths, commit_ref,
  	    worktree, fileindex, tmp_branch, orig_commit, new_logmsg, repo);
  done:
  	if (commit_ref)
  		got_ref_close(commit_ref);
  	free(commit_ref_name);
  	return err;
  }
  
  const struct got_error *
  got_worktree_rebase_postpone(struct got_worktree *worktree,
      struct got_fileindex *fileindex)
  {
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	return lock_worktree(worktree, LOCK_SH);
  }
  
  static const struct got_error *
  delete_ref(const char *name, struct got_repository *repo)
  {
  	const struct got_error *err;
  	struct got_reference *ref;
  
  	err = got_ref_open(&ref, repo, name, 0);
  	if (err) {
  		if (err->code == GOT_ERR_NOT_REF)
  			return NULL;
  		return err;
  	}
  
  	err = got_ref_delete(ref, repo);
  	got_ref_close(ref);
  	return err;
  }
  
  static const struct got_error *
  delete_rebase_refs(struct got_worktree *worktree, struct got_repository *repo)
  {
  	const struct got_error *err;
  	char *tmp_branch_name = NULL, *new_base_branch_ref_name = NULL;
  	char *branch_ref_name = NULL, *commit_ref_name = NULL;
  
  	err = get_rebase_tmp_ref_name(&tmp_branch_name, worktree);
  	if (err)
  		goto done;
  	err = delete_ref(tmp_branch_name, repo);
  	if (err)
  		goto done;
  
  	err = get_newbase_symref_name(&new_base_branch_ref_name, worktree);
  	if (err)
  		goto done;
  	err = delete_ref(new_base_branch_ref_name, repo);
  	if (err)
  		goto done;
  
  	err = get_rebase_branch_symref_name(&branch_ref_name, worktree);
  	if (err)
  		goto done;
  	err = delete_ref(branch_ref_name, repo);
  	if (err)
  		goto done;
  
  	err = get_rebase_commit_ref_name(&commit_ref_name, worktree);
  	if (err)
  		goto done;
  	err = delete_ref(commit_ref_name, repo);
  	if (err)
  		goto done;
  
  done:
  	free(tmp_branch_name);
  	free(new_base_branch_ref_name);
  	free(branch_ref_name);
  	free(commit_ref_name);
  	return err;
  }
  
  const struct got_error *
  create_backup_ref(const char *backup_ref_prefix, struct got_reference *branch,
      struct got_object_id *new_commit_id, struct got_repository *repo)
  {
  	const struct got_error *err;
  	struct got_reference *ref = NULL;
  	struct got_object_id *old_commit_id = NULL;
  	const char *branch_name = NULL;
  	char *new_id_str = NULL;
  	char *refname = NULL;
  
  	branch_name = got_ref_get_name(branch);
  	if (strncmp(branch_name, "refs/heads/", 11) != 0)
  		return got_error(GOT_ERR_BAD_REF_NAME); /* should not happen */
  	branch_name += 11;
  
  	err = got_object_id_str(&new_id_str, new_commit_id);
  	if (err)
  		return err;
  
  	if (asprintf(&refname, "%s/%s/%s", backup_ref_prefix, branch_name,
  	    new_id_str) == -1) {
  		err = got_error_from_errno("asprintf");
  		goto done;
  	}
  
  	err = got_ref_resolve(&old_commit_id, repo, branch);
  	if (err)
  		goto done;
  
  	err = got_ref_alloc(&ref, refname, old_commit_id);
  	if (err)
  		goto done;
  
  	err = got_ref_write(ref, repo);
  done:
  	free(new_id_str);
  	free(refname);
  	free(old_commit_id);
  	if (ref)
  		got_ref_close(ref);
  	return err;
  }
  
  const struct got_error *
  got_worktree_rebase_complete(struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_reference *new_base_branch,
      struct got_reference *tmp_branch, struct got_reference *rebased_branch,
      struct got_repository *repo, int create_backup)
  {
  	const struct got_error *err, *unlockerr, *sync_err;
  	struct got_object_id *new_head_commit_id = NULL;
  	char *fileindex_path = NULL;
  
  	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
  	if (err)
  		return err;
  
  	if (create_backup) {
  		err = create_backup_ref(GOT_WORKTREE_REBASE_BACKUP_REF_PREFIX,
  		    rebased_branch, new_head_commit_id, repo);
  		if (err)
  			goto done;
  	}
  
  	err = got_ref_change_ref(rebased_branch, new_head_commit_id);
  	if (err)
  		goto done;
  
  	err = got_ref_write(rebased_branch, repo);
  	if (err)
  		goto done;
  
  	err = got_worktree_set_head_ref(worktree, rebased_branch);
  	if (err)
  		goto done;
  
  	err = delete_rebase_refs(worktree, repo);
  	if (err)
  		goto done;
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		goto done;
  	err = bump_base_commit_id_everywhere(worktree, fileindex, NULL, NULL);
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	got_fileindex_free(fileindex);
  	free(fileindex_path);
  	free(new_head_commit_id);
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  const struct got_error *
  got_worktree_rebase_abort(struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_repository *repo,
      struct got_reference *new_base_branch,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	const struct got_error *err, *unlockerr, *sync_err;
  	struct got_reference *resolved = NULL;
  	struct got_object_id *commit_id = NULL;
  	struct got_commit_object *commit = NULL;
  	char *fileindex_path = NULL;
  	struct revert_file_args rfa;
  	struct got_object_id *tree_id = NULL;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = got_object_open_as_commit(&commit, repo,
  	    worktree->base_commit_id);
  	if (err)
  		goto done;
  
  	err = got_ref_open(&resolved, repo,
  	    got_ref_get_symref_target(new_base_branch), 0);
  	if (err)
  		goto done;
  
  	err = got_worktree_set_head_ref(worktree, resolved);
  	if (err)
  		goto done;
  
  	/*
  	 * XXX commits to the base branch could have happened while
  	 * we were busy rebasing; should we store the original commit ID
  	 * when rebase begins and read it back here?
  	 */
  	err = got_ref_resolve(&commit_id, repo, resolved);
  	if (err)
  		goto done;
  
  	err = got_worktree_set_base_commit_id(worktree, repo, commit_id);
  	if (err)
  		goto done;
  
  	err = got_object_id_by_path(&tree_id, repo, commit,
  	    worktree->path_prefix);
  	if (err)
  		goto done;
  
  	err = delete_rebase_refs(worktree, repo);
  	if (err)
  		goto done;
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	rfa.worktree = worktree;
  	rfa.fileindex = fileindex;
  	rfa.progress_cb = progress_cb;
  	rfa.progress_arg = progress_arg;
  	rfa.patch_cb = NULL;
  	rfa.patch_arg = NULL;
  	rfa.repo = repo;
  	rfa.unlink_added_files = 0;
  	err = worktree_status(worktree, "", fileindex, repo,
  	    revert_file, &rfa, NULL, NULL, 1, 0);
  	if (err)
  		goto sync;
  
  	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
  	    repo, progress_cb, progress_arg, NULL, NULL);
  sync:
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	got_ref_close(resolved);
  	free(tree_id);
  	free(commit_id);
  	if (commit)
  		got_object_commit_close(commit);
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	free(fileindex_path);
  
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  const struct got_error *
  got_worktree_histedit_prepare(struct got_reference **tmp_branch,
      struct got_reference **branch_ref, struct got_object_id **base_commit_id,
      struct got_fileindex **fileindex, struct got_worktree *worktree,
      struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	char *tmp_branch_name = NULL;
  	char *branch_ref_name = NULL;
  	char *base_commit_ref_name = NULL;
  	char *fileindex_path = NULL;
  	struct check_rebase_ok_arg ok_arg;
  	struct got_reference *wt_branch = NULL;
  	struct got_reference *base_commit_ref = NULL;
  
  	*tmp_branch = NULL;
  	*branch_ref = NULL;
  	*base_commit_id = NULL;
  	*fileindex = NULL;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = open_fileindex(fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	ok_arg.worktree = worktree;
  	ok_arg.repo = repo;
  	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
  	    &ok_arg);
  	if (err)
  		goto done;
  
  	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
  	if (err)
  		goto done;
  
  	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
  	if (err)
  		goto done;
  
  	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
  	    worktree);
  	if (err)
  		goto done;
  
  	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
  	    0);
  	if (err)
  		goto done;
  
  	err = got_ref_alloc_symref(branch_ref, branch_ref_name, wt_branch);
  	if (err)
  		goto done;
  
  	err = got_ref_write(*branch_ref, repo);
  	if (err)
  		goto done;
  
  	err = got_ref_alloc(&base_commit_ref, base_commit_ref_name,
  	    worktree->base_commit_id);
  	if (err)
  		goto done;
  	err = got_ref_write(base_commit_ref, repo);
  	if (err)
  		goto done;
  	*base_commit_id = got_object_id_dup(worktree->base_commit_id);
  	if (*base_commit_id == NULL) {
  		err = got_error_from_errno("got_object_id_dup");
  		goto done;
  	}
  
  	err = got_ref_alloc(tmp_branch, tmp_branch_name,
  	    worktree->base_commit_id);
  	if (err)
  		goto done;
  	err = got_ref_write(*tmp_branch, repo);
  	if (err)
  		goto done;
  
  	err = got_worktree_set_head_ref(worktree, *tmp_branch);
  	if (err)
  		goto done;
  done:
  	free(fileindex_path);
  	free(tmp_branch_name);
  	free(branch_ref_name);
  	free(base_commit_ref_name);
  	if (wt_branch)
  		got_ref_close(wt_branch);
  	if (err) {
  		if (*branch_ref) {
  			got_ref_close(*branch_ref);
  			*branch_ref = NULL;
  		}
  		if (*tmp_branch) {
  			got_ref_close(*tmp_branch);
  			*tmp_branch = NULL;
  		}
  		free(*base_commit_id);
  		if (*fileindex) {
  			got_fileindex_free(*fileindex);
  			*fileindex = NULL;
  		}
  		lock_worktree(worktree, LOCK_SH);
  	}
  	return err;
  }
  
  const struct got_error *
  got_worktree_histedit_postpone(struct got_worktree *worktree,
      struct got_fileindex *fileindex)
  {
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	return lock_worktree(worktree, LOCK_SH);
  }
  
  const struct got_error *
  got_worktree_histedit_in_progress(int *in_progress,
      struct got_worktree *worktree)
  {
  	const struct got_error *err;
  	char *tmp_branch_name = NULL;
  
  	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
  	if (err)
  		return err;
  
  	*in_progress = (strcmp(tmp_branch_name, worktree->head_ref_name) == 0);
  	free(tmp_branch_name);
  	return NULL;
  }
  
  const struct got_error *
  got_worktree_histedit_continue(struct got_object_id **commit_id,
      struct got_reference **tmp_branch, struct got_reference **branch_ref,
      struct got_object_id **base_commit_id, struct got_fileindex **fileindex,
      struct got_worktree *worktree, struct got_repository *repo)
  {
  	const struct got_error *err;
  	char *commit_ref_name = NULL, *base_commit_ref_name = NULL;
  	char *tmp_branch_name = NULL, *branch_ref_name = NULL;
  	struct got_reference *commit_ref = NULL;
  	struct got_reference *base_commit_ref = NULL;
  	char *fileindex_path = NULL;
  	int have_staged_files = 0;
  
  	*commit_id = NULL;
  	*tmp_branch = NULL;
  	*base_commit_id = NULL;
  	*fileindex = NULL;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = open_fileindex(fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	err = got_fileindex_for_each_entry_safe(*fileindex, check_staged_file,
  	    &have_staged_files);
  	if (err && err->code != GOT_ERR_CANCELLED)
  		goto done;
  	if (have_staged_files) {
  		err = got_error(GOT_ERR_STAGED_PATHS);
  		goto done;
  	}
  
  	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
  	if (err)
  		goto done;
  
  	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
  	if (err)
  		goto done;
  
  	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
  	if (err)
  		goto done;
  
  	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
  	    worktree);
  	if (err)
  		goto done;
  
  	err = got_ref_open(branch_ref, repo, branch_ref_name, 0);
  	if (err)
  		goto done;
  
  	err = got_ref_open(&commit_ref, repo, commit_ref_name, 0);
  	if (err)
  		goto done;
  	err = got_ref_resolve(commit_id, repo, commit_ref);
  	if (err)
  		goto done;
  
  	err = got_ref_open(&base_commit_ref, repo, base_commit_ref_name, 0);
  	if (err)
  		goto done;
  	err = got_ref_resolve(base_commit_id, repo, base_commit_ref);
  	if (err)
  		goto done;
  
  	err = got_ref_open(tmp_branch, repo, tmp_branch_name, 0);
  	if (err)
  		goto done;
  done:
  	free(commit_ref_name);
  	free(branch_ref_name);
  	free(fileindex_path);
  	if (commit_ref)
  		got_ref_close(commit_ref);
  	if (base_commit_ref)
  		got_ref_close(base_commit_ref);
  	if (err) {
  		free(*commit_id);
  		*commit_id = NULL;
  		free(*base_commit_id);
  		*base_commit_id = NULL;
  		if (*tmp_branch) {
  			got_ref_close(*tmp_branch);
  			*tmp_branch = NULL;
  		}
  		if (*fileindex) {
  			got_fileindex_free(*fileindex);
  			*fileindex = NULL;
  		}
  		lock_worktree(worktree, LOCK_EX);
  	}
  	return err;
  }
  
  static const struct got_error *
  delete_histedit_refs(struct got_worktree *worktree, struct got_repository *repo)
  {
  	const struct got_error *err;
  	char *tmp_branch_name = NULL, *base_commit_ref_name = NULL;
  	char *branch_ref_name = NULL, *commit_ref_name = NULL;
  
  	err = get_histedit_tmp_ref_name(&tmp_branch_name, worktree);
  	if (err)
  		goto done;
  	err = delete_ref(tmp_branch_name, repo);
  	if (err)
  		goto done;
  
  	err = get_histedit_base_commit_ref_name(&base_commit_ref_name,
  	    worktree);
  	if (err)
  		goto done;
  	err = delete_ref(base_commit_ref_name, repo);
  	if (err)
  		goto done;
  
  	err = get_histedit_branch_symref_name(&branch_ref_name, worktree);
  	if (err)
  		goto done;
  	err = delete_ref(branch_ref_name, repo);
  	if (err)
  		goto done;
  
  	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
  	if (err)
  		goto done;
  	err = delete_ref(commit_ref_name, repo);
  	if (err)
  		goto done;
  done:
  	free(tmp_branch_name);
  	free(base_commit_ref_name);
  	free(branch_ref_name);
  	free(commit_ref_name);
  	return err;
  }
  
  const struct got_error *
  got_worktree_histedit_abort(struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_repository *repo,
      struct got_reference *branch, struct got_object_id *base_commit_id,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	const struct got_error *err, *unlockerr, *sync_err;
  	struct got_reference *resolved = NULL;
  	char *fileindex_path = NULL;
  	struct got_commit_object *commit = NULL;
  	struct got_object_id *tree_id = NULL;
  	struct revert_file_args rfa;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = got_object_open_as_commit(&commit, repo,
  	    worktree->base_commit_id);
  	if (err)
  		goto done;
  
  	err = got_ref_open(&resolved, repo,
  	    got_ref_get_symref_target(branch), 0);
  	if (err)
  		goto done;
  
  	err = got_worktree_set_head_ref(worktree, resolved);
  	if (err)
  		goto done;
  
  	err = got_worktree_set_base_commit_id(worktree, repo, base_commit_id);
  	if (err)
  		goto done;
  
  	err = got_object_id_by_path(&tree_id, repo, commit,
  	    worktree->path_prefix);
  	if (err)
  		goto done;
  
  	err = delete_histedit_refs(worktree, repo);
  	if (err)
  		goto done;
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	rfa.worktree = worktree;
  	rfa.fileindex = fileindex;
  	rfa.progress_cb = progress_cb;
  	rfa.progress_arg = progress_arg;
  	rfa.patch_cb = NULL;
  	rfa.patch_arg = NULL;
  	rfa.repo = repo;
  	rfa.unlink_added_files = 0;
  	err = worktree_status(worktree, "", fileindex, repo,
  	    revert_file, &rfa, NULL, NULL, 1, 0);
  	if (err)
  		goto sync;
  
  	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
  	    repo, progress_cb, progress_arg, NULL, NULL);
  sync:
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	got_ref_close(resolved);
  	free(tree_id);
  	free(fileindex_path);
  
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  const struct got_error *
  got_worktree_histedit_complete(struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_reference *tmp_branch,
      struct got_reference *edited_branch, struct got_repository *repo)
  {
  	const struct got_error *err, *unlockerr, *sync_err;
  	struct got_object_id *new_head_commit_id = NULL;
  	struct got_reference *resolved = NULL;
  	char *fileindex_path = NULL;
  
  	err = got_ref_resolve(&new_head_commit_id, repo, tmp_branch);
  	if (err)
  		return err;
  
  	err = got_ref_open(&resolved, repo,
  	    got_ref_get_symref_target(edited_branch), 0);
  	if (err)
  		goto done;
  
  	err = create_backup_ref(GOT_WORKTREE_HISTEDIT_BACKUP_REF_PREFIX,
  	    resolved, new_head_commit_id, repo);
  	if (err)
  		goto done;
  
  	err = got_ref_change_ref(resolved, new_head_commit_id);
  	if (err)
  		goto done;
  
  	err = got_ref_write(resolved, repo);
  	if (err)
  		goto done;
  
  	err = got_worktree_set_head_ref(worktree, resolved);
  	if (err)
  		goto done;
  
  	err = delete_histedit_refs(worktree, repo);
  	if (err)
  		goto done;
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		goto done;
  	err = bump_base_commit_id_everywhere(worktree, fileindex, NULL, NULL);
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	got_fileindex_free(fileindex);
  	free(fileindex_path);
  	free(new_head_commit_id);
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  const struct got_error *
  got_worktree_histedit_skip_commit(struct got_worktree *worktree,
      struct got_object_id *commit_id, struct got_repository *repo)
  {
  	const struct got_error *err;
  	char *commit_ref_name;
  
  	err = get_histedit_commit_ref_name(&commit_ref_name, worktree);
  	if (err)
  		return err;
  
  	err = store_commit_id(commit_ref_name, commit_id, 0, repo);
  	if (err)
  		goto done;
  
  	err = delete_ref(commit_ref_name, repo);
  done:
  	free(commit_ref_name);
  	return err;
  }
  
  const struct got_error *
  got_worktree_integrate_prepare(struct got_fileindex **fileindex,
      struct got_reference **branch_ref, struct got_reference **base_branch_ref,
      struct got_worktree *worktree, const char *refname,
      struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	char *fileindex_path = NULL;
  	struct check_rebase_ok_arg ok_arg;
  
  	*fileindex = NULL;
  	*branch_ref = NULL;
  	*base_branch_ref = NULL;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	if (strcmp(refname, got_worktree_get_head_ref_name(worktree)) == 0) {
  		err = got_error_msg(GOT_ERR_SAME_BRANCH,
  		    "cannot integrate a branch into itself; "
  		    "update -b or different branch name required");
  		goto done;
  	}
  
  	err = open_fileindex(fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	/* Preconditions are the same as for rebase. */
  	ok_arg.worktree = worktree;
  	ok_arg.repo = repo;
  	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
  	    &ok_arg);
  	if (err)
  		goto done;
  
  	err = got_ref_open(branch_ref, repo, refname, 1);
  	if (err)
  		goto done;
  
  	err = got_ref_open(base_branch_ref, repo,
  	    got_worktree_get_head_ref_name(worktree), 1);
  done:
  	if (err) {
  		if (*branch_ref) {
  			got_ref_close(*branch_ref);
  			*branch_ref = NULL;
  		}
  		if (*base_branch_ref) {
  			got_ref_close(*base_branch_ref);
  			*base_branch_ref = NULL;
  		}
  		if (*fileindex) {
  			got_fileindex_free(*fileindex);
  			*fileindex = NULL;
  		}
  		lock_worktree(worktree, LOCK_SH);
  	}
  	return err;
  }
  
  const struct got_error *
  got_worktree_integrate_continue(struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_repository *repo,
      struct got_reference *branch_ref, struct got_reference *base_branch_ref,
      got_worktree_checkout_cb progress_cb, void *progress_arg,
      got_cancel_cb cancel_cb, void *cancel_arg)
  {
  	const struct got_error *err = NULL, *sync_err, *unlockerr;
  	char *fileindex_path = NULL;
  	struct got_object_id *tree_id = NULL, *commit_id = NULL;
  	struct got_commit_object *commit =  NULL;
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	err = got_ref_resolve(&commit_id, repo, branch_ref);
  	if (err)
  		goto done;
  
  	err = got_object_open_as_commit(&commit, repo, commit_id);
  	if (err)
  		goto done;
  
  	err = got_object_id_by_path(&tree_id, repo, commit,
  	    worktree->path_prefix);
  	if (err)
  		goto done;
  
  	err = got_worktree_set_base_commit_id(worktree, repo, commit_id);
  	if (err)
  		goto done;
  
  	err = checkout_files(worktree, fileindex, "", tree_id, NULL, repo,
  	    progress_cb, progress_arg, cancel_cb, cancel_arg);
  	if (err)
  		goto sync;
  
  	err = got_ref_change_ref(base_branch_ref, commit_id);
  	if (err)
  		goto sync;
  
  	err = got_ref_write(base_branch_ref, repo);
  	if (err)
  		goto sync;
  
  	err = bump_base_commit_id_everywhere(worktree, fileindex, NULL, NULL);
  sync:
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  
  done:
  	unlockerr = got_ref_unlock(branch_ref);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	got_ref_close(branch_ref);
  
  	unlockerr = got_ref_unlock(base_branch_ref);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	got_ref_close(base_branch_ref);
  
  	got_fileindex_free(fileindex);
  	free(fileindex_path);
  	free(tree_id);
  	if (commit)
  		got_object_commit_close(commit);
  
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  const struct got_error *
  got_worktree_integrate_abort(struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_repository *repo,
      struct got_reference *branch_ref, struct got_reference *base_branch_ref)
  {
  	const struct got_error *err = NULL, *unlockerr = NULL;
  
  	got_fileindex_free(fileindex);
  
  	err = lock_worktree(worktree, LOCK_SH);
  
  	unlockerr = got_ref_unlock(branch_ref);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	got_ref_close(branch_ref);
  
  	unlockerr = got_ref_unlock(base_branch_ref);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	got_ref_close(base_branch_ref);
  
  	return err;
  }
  
  const struct got_error *
  got_worktree_merge_postpone(struct got_worktree *worktree,
      struct got_fileindex *fileindex)
  {
  	const struct got_error *err, *sync_err;
  	char *fileindex_path = NULL;
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  
  	err = lock_worktree(worktree, LOCK_SH);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	got_fileindex_free(fileindex);
  	free(fileindex_path);
  	return err;
  }
  
  static const struct got_error *
  delete_merge_refs(struct got_worktree *worktree, struct got_repository *repo)
  {
  	const struct got_error *err;
  	char *branch_refname = NULL, *commit_refname = NULL;
  
  	err = get_merge_branch_ref_name(&branch_refname, worktree);
  	if (err)
  		goto done;
  	err = delete_ref(branch_refname, repo);
  	if (err)
  		goto done;
  
  	err = get_merge_commit_ref_name(&commit_refname, worktree);
  	if (err)
  		goto done;
  	err = delete_ref(commit_refname, repo);
  	if (err)
  		goto done;
  
  done:
  	free(branch_refname);
  	free(commit_refname);
  	return err;
  }
  
  struct merge_commit_msg_arg {
  	struct got_worktree *worktree;
  	const char *branch_name;
  };
  
  static const struct got_error *
  merge_commit_msg_cb(struct got_pathlist_head *commitable_paths, char **logmsg,
      void *arg)
  {
  	struct merge_commit_msg_arg *a = arg;
  
  	if (asprintf(logmsg, "merge %s into %s\n", a->branch_name,
  	    got_worktree_get_head_ref_name(a->worktree)) == -1)
  		return got_error_from_errno("asprintf");
  
  	return NULL;
  }
  
  
  const struct got_error *
  got_worktree_merge_branch(struct got_worktree *worktree,
      struct got_fileindex *fileindex,
      struct got_object_id *yca_commit_id,
      struct got_object_id *branch_tip,
      struct got_repository *repo, got_worktree_checkout_cb progress_cb,
      void *progress_arg, got_cancel_cb cancel_cb, void *cancel_arg)
  {
  	const struct got_error *err;
  	char *fileindex_path = NULL;
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	err = got_fileindex_for_each_entry_safe(fileindex, check_mixed_commits,
  	    worktree);
  	if (err)
  		goto done;
  
  	err = merge_files(worktree, fileindex, fileindex_path, yca_commit_id,
  	    branch_tip, repo, progress_cb, progress_arg,
  	    cancel_cb, cancel_arg);
  done:
  	free(fileindex_path);
  	return err;
  }
  
  const struct got_error *
  got_worktree_merge_commit(struct got_object_id **new_commit_id,
      struct got_worktree *worktree, struct got_fileindex *fileindex,
      const char *author, const char *committer, int allow_bad_symlinks,
      struct got_object_id *branch_tip, const char *branch_name,
      struct got_repository *repo,
      got_worktree_status_cb status_cb, void *status_arg)
  
  {
  	const struct got_error *err = NULL, *sync_err;
  	struct got_pathlist_head commitable_paths;
  	struct collect_commitables_arg cc_arg;
  	struct got_pathlist_entry *pe;
  	struct got_reference *head_ref = NULL;
  	struct got_object_id *head_commit_id = NULL;
  	int have_staged_files = 0;
  	struct merge_commit_msg_arg mcm_arg;
  	char *fileindex_path = NULL;
  
  	*new_commit_id = NULL;
  
  	TAILQ_INIT(&commitable_paths);
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	err = got_ref_open(&head_ref, repo, worktree->head_ref_name, 0);
  	if (err)
  		goto done;
  
  	err = got_ref_resolve(&head_commit_id, repo, head_ref);
  	if (err)
  		goto done;
  
  	err = got_fileindex_for_each_entry_safe(fileindex, check_staged_file,
  	    &have_staged_files);
  	if (err && err->code != GOT_ERR_CANCELLED)
  		goto done;
  	if (have_staged_files) {
  		err = got_error(GOT_ERR_MERGE_STAGED_PATHS);
  		goto done;
  	}
  
  	cc_arg.commitable_paths = &commitable_paths;
  	cc_arg.worktree = worktree;
  	cc_arg.fileindex = fileindex;
  	cc_arg.repo = repo;
  	cc_arg.have_staged_files = have_staged_files;
  	cc_arg.allow_bad_symlinks = allow_bad_symlinks;
  	err = worktree_status(worktree, "", fileindex, repo,
  	    collect_commitables, &cc_arg, NULL, NULL, 1, 0);
  	if (err)
  		goto done;
  
  	if (TAILQ_EMPTY(&commitable_paths)) {
  		err = got_error_fmt(GOT_ERR_COMMIT_NO_CHANGES,
  		    "merge of %s cannot proceed", branch_name);
  		goto done;
  	}
  
  	TAILQ_FOREACH(pe, &commitable_paths, entry) {
  		struct got_commitable *ct = pe->data;
  		const char *ct_path = ct->in_repo_path;
  
  		while (ct_path[0] == '/')
  			ct_path++;
  		err = check_out_of_date(ct_path, ct->status,
  		    ct->staged_status, ct->base_blob_id, ct->base_commit_id,
  		    head_commit_id, repo, GOT_ERR_MERGE_COMMIT_OUT_OF_DATE);
  		if (err)
  			goto done;
  
  	}
  
  	mcm_arg.worktree = worktree;
  	mcm_arg.branch_name = branch_name;
  	err = commit_worktree(new_commit_id, &commitable_paths,
  	    head_commit_id, branch_tip, worktree, author, committer,
  	    merge_commit_msg_cb, &mcm_arg, status_cb, status_arg, repo);
  	if (err)
  		goto done;
  
  	err = update_fileindex_after_commit(worktree, &commitable_paths,
  	    *new_commit_id, fileindex, have_staged_files);
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	TAILQ_FOREACH(pe, &commitable_paths, entry) {
  		struct got_commitable *ct = pe->data;
  		free_commitable(ct);
  	}
  	got_pathlist_free(&commitable_paths);
  	free(fileindex_path);
  	return err;
  }
  
  const struct got_error *
  got_worktree_merge_complete(struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_repository *repo)
  {
  	const struct got_error *err, *unlockerr, *sync_err;
  	char *fileindex_path = NULL;
  
  	err = delete_merge_refs(worktree, repo);
  	if (err)
  		goto done;
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		goto done;
  	err = bump_base_commit_id_everywhere(worktree, fileindex, NULL, NULL);
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	got_fileindex_free(fileindex);
  	free(fileindex_path);
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  const struct got_error *
  got_worktree_merge_in_progress(int *in_progress, struct got_worktree *worktree,
      struct got_repository *repo)
  {
  	const struct got_error *err;
  	char *branch_refname = NULL;
  	struct got_reference *branch_ref = NULL;
  
  	*in_progress = 0;
  
  	err = get_merge_branch_ref_name(&branch_refname, worktree);
  	if (err)
  		return err;
  	err = got_ref_open(&branch_ref, repo, branch_refname, 0);
  	free(branch_refname);
  	if (err) {
  		if (err->code != GOT_ERR_NOT_REF)
  			return err;
  	} else
  		*in_progress = 1;
  
  	return NULL;
  }
  
  const struct got_error *got_worktree_merge_prepare(
      struct got_fileindex **fileindex, struct got_worktree *worktree,
      struct got_reference *branch, struct got_repository *repo)
  {
  	const struct got_error *err = NULL;
  	char *fileindex_path = NULL;
  	char *branch_refname = NULL, *commit_refname = NULL;
  	struct got_reference *wt_branch = NULL, *branch_ref = NULL;
  	struct got_reference *commit_ref = NULL;
  	struct got_object_id *branch_tip = NULL, *wt_branch_tip = NULL;
  	struct check_rebase_ok_arg ok_arg;
  
  	*fileindex = NULL;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = open_fileindex(fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	/* Preconditions are the same as for rebase. */
  	ok_arg.worktree = worktree;
  	ok_arg.repo = repo;
  	err = got_fileindex_for_each_entry_safe(*fileindex, check_rebase_ok,
  	    &ok_arg);
  	if (err)
  		goto done;
  
  	err = get_merge_branch_ref_name(&branch_refname, worktree);
  	if (err)
  		return err;
  
  	err = get_merge_commit_ref_name(&commit_refname, worktree);
  	if (err)
  		return err;
  
  	err = got_ref_open(&wt_branch, repo, worktree->head_ref_name,
  	    0);
  	if (err)
  		goto done;
  
  	err = got_ref_resolve(&wt_branch_tip, repo, wt_branch);
  	if (err)
  		goto done;
  
  	if (got_object_id_cmp(worktree->base_commit_id, wt_branch_tip) != 0) {
  		err = got_error(GOT_ERR_MERGE_OUT_OF_DATE);
  		goto done;
  	}
  
  	err = got_ref_resolve(&branch_tip, repo, branch);
  	if (err)
  		goto done;
  
  	err = got_ref_alloc_symref(&branch_ref, branch_refname, branch);
  	if (err)
  		goto done;
  	err = got_ref_write(branch_ref, repo);
  	if (err)
  		goto done;
  
  	err = got_ref_alloc(&commit_ref, commit_refname, branch_tip);
  	if (err)
  		goto done;
  	err = got_ref_write(commit_ref, repo);
  	if (err)
  		goto done;
  
  done:
  	free(branch_refname);
  	free(commit_refname);
  	free(fileindex_path);
  	if (branch_ref)
  		got_ref_close(branch_ref);
  	if (commit_ref)
  		got_ref_close(commit_ref);
  	if (wt_branch)
  		got_ref_close(wt_branch);
  	free(wt_branch_tip);
  	if (err) {
  		if (*fileindex) {
  			got_fileindex_free(*fileindex);
  			*fileindex = NULL;
  		}
  		lock_worktree(worktree, LOCK_SH);
  	}
  	return err;
  }
  
  const struct got_error *
  got_worktree_merge_continue(char **branch_name,
      struct got_object_id **branch_tip, struct got_fileindex **fileindex,
      struct got_worktree *worktree, struct got_repository *repo)
  {
  	const struct got_error *err;
  	char *commit_refname = NULL, *branch_refname = NULL;
  	struct got_reference *commit_ref = NULL, *branch_ref = NULL;
  	char *fileindex_path = NULL;
  	int have_staged_files = 0;
  
  	*branch_name = NULL;
  	*branch_tip = NULL;
  	*fileindex = NULL;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = open_fileindex(fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	err = got_fileindex_for_each_entry_safe(*fileindex, check_staged_file,
  	    &have_staged_files);
  	if (err && err->code != GOT_ERR_CANCELLED)
  		goto done;
  	if (have_staged_files) {
  		err = got_error(GOT_ERR_STAGED_PATHS);
  		goto done;
  	}
  
  	err = get_merge_branch_ref_name(&branch_refname, worktree);
  	if (err)
  		goto done;
  
  	err = get_merge_commit_ref_name(&commit_refname, worktree);
  	if (err)
  		goto done;
  
  	err = got_ref_open(&branch_ref, repo, branch_refname, 0);
  	if (err)
  		goto done;
  
  	if (!got_ref_is_symbolic(branch_ref)) {
  		err = got_error_fmt(GOT_ERR_BAD_REF_TYPE,
  		    "%s is not a symbolic reference",
  		    got_ref_get_name(branch_ref));
  		goto done;
  	}
  	*branch_name = strdup(got_ref_get_symref_target(branch_ref));
  	if (*branch_name == NULL) {
  		err = got_error_from_errno("strdup");
  		goto done;
  	}
  
  	err = got_ref_open(&commit_ref, repo, commit_refname, 0);
  	if (err)
  		goto done;
  
  	err = got_ref_resolve(branch_tip, repo, commit_ref);
  	if (err)
  		goto done;
  done:
  	free(commit_refname);
  	free(branch_refname);
  	free(fileindex_path);
  	if (commit_ref)
  		got_ref_close(commit_ref);
  	if (branch_ref)
  		got_ref_close(branch_ref);
  	if (err) {
  		if (*branch_name) {
  			free(*branch_name);
  			*branch_name = NULL;
  		}
  		free(*branch_tip);
  		*branch_tip = NULL;
  		if (*fileindex) {
  			got_fileindex_free(*fileindex);
  			*fileindex = NULL;
  		}
  		lock_worktree(worktree, LOCK_SH);
  	}
  	return err;
  }
  
  const struct got_error *
  got_worktree_merge_abort(struct got_worktree *worktree,
      struct got_fileindex *fileindex, struct got_repository *repo,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	const struct got_error *err, *unlockerr, *sync_err;
  	struct got_object_id *commit_id = NULL;
  	struct got_commit_object *commit = NULL;
  	char *fileindex_path = NULL;
  	struct revert_file_args rfa;
  	struct got_object_id *tree_id = NULL;
  
  	err = got_object_open_as_commit(&commit, repo,
  	    worktree->base_commit_id);
  	if (err)
  		goto done;
  
  	err = got_object_id_by_path(&tree_id, repo, commit,
  	    worktree->path_prefix);
  	if (err)
  		goto done;
  
  	err = delete_merge_refs(worktree, repo);
  	if (err)
  		goto done;
  
  	err = get_fileindex_path(&fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	rfa.worktree = worktree;
  	rfa.fileindex = fileindex;
  	rfa.progress_cb = progress_cb;
  	rfa.progress_arg = progress_arg;
  	rfa.patch_cb = NULL;
  	rfa.patch_arg = NULL;
  	rfa.repo = repo;
  	rfa.unlink_added_files = 1;
  	err = worktree_status(worktree, "", fileindex, repo,
  	    revert_file, &rfa, NULL, NULL, 1, 0);
  	if (err)
  		goto sync;
  
  	err = checkout_files(worktree, fileindex, "", tree_id, NULL,
  	    repo, progress_cb, progress_arg, NULL, NULL);
  sync:
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	free(tree_id);
  	free(commit_id);
  	if (commit)
  		got_object_commit_close(commit);
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	free(fileindex_path);
  
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  struct check_stage_ok_arg {
  	struct got_object_id *head_commit_id;
  	struct got_worktree *worktree;
  	struct got_fileindex *fileindex;
  	struct got_repository *repo;
  	int have_changes;
  };
  
  const struct got_error *
  check_stage_ok(void *arg, unsigned char status,
      unsigned char staged_status, const char *relpath,
      struct got_object_id *blob_id, struct got_object_id *staged_blob_id,
      struct got_object_id *commit_id, int dirfd, const char *de_name)
  {
  	struct check_stage_ok_arg *a = arg;
  	const struct got_error *err = NULL;
  	struct got_fileindex_entry *ie;
  	struct got_object_id base_commit_id;
  	struct got_object_id *base_commit_idp = NULL;
  	char *in_repo_path = NULL, *p;
  
  	if (status == GOT_STATUS_UNVERSIONED ||
  	    status == GOT_STATUS_NO_CHANGE)
  		return NULL;
  	if (status == GOT_STATUS_NONEXISTENT)
  		return got_error_set_errno(ENOENT, relpath);
  
  	ie = got_fileindex_entry_get(a->fileindex, relpath, strlen(relpath));
  	if (ie == NULL)
  		return got_error_path(relpath, GOT_ERR_FILE_STATUS);
  
  	if (asprintf(&in_repo_path, "%s%s%s", a->worktree->path_prefix,
  	    got_path_is_root_dir(a->worktree->path_prefix) ? "" : "/",
  	    relpath) == -1)
  		return got_error_from_errno("asprintf");
  
  	if (got_fileindex_entry_has_commit(ie)) {
  		memcpy(base_commit_id.sha1, ie->commit_sha1,
  		    SHA1_DIGEST_LENGTH);
  		base_commit_idp = &base_commit_id;
  	}
  
  	if (status == GOT_STATUS_CONFLICT) {
  		err = got_error_path(ie->path, GOT_ERR_STAGE_CONFLICT);
  		goto done;
  	} else if (status != GOT_STATUS_ADD &&
  	    status != GOT_STATUS_MODIFY &&
  	    status != GOT_STATUS_DELETE) {
  		err = got_error_path(ie->path, GOT_ERR_FILE_STATUS);
  		goto done;
  	}
  
  	a->have_changes = 1;
  
  	p = in_repo_path;
  	while (p[0] == '/')
  		p++;
  	err = check_out_of_date(p, status, staged_status,
  	    blob_id, base_commit_idp, a->head_commit_id, a->repo,
  	    GOT_ERR_STAGE_OUT_OF_DATE);
  done:
  	free(in_repo_path);
  	return err;
  }
  
  struct stage_path_arg {
  	struct got_worktree *worktree;
  	struct got_fileindex *fileindex;
  	struct got_repository *repo;
  	got_worktree_status_cb status_cb;
  	void *status_arg;
  	got_worktree_patch_cb patch_cb;
  	void *patch_arg;
  	int staged_something;
  	int allow_bad_symlinks;
  };
  
  static const struct got_error *
  stage_path(void *arg, unsigned char status,
      unsigned char staged_status, const char *relpath,
      struct got_object_id *blob_id, struct got_object_id *staged_blob_id,
      struct got_object_id *commit_id, int dirfd, const char *de_name)
  {
  	struct stage_path_arg *a = arg;
  	const struct got_error *err = NULL;
  	struct got_fileindex_entry *ie;
  	char *ondisk_path = NULL, *path_content = NULL;
  	uint32_t stage;
  	struct got_object_id *new_staged_blob_id = NULL;
  	struct stat sb;
  
  	if (status == GOT_STATUS_UNVERSIONED)
  		return NULL;
  
  	ie = got_fileindex_entry_get(a->fileindex, relpath, strlen(relpath));
  	if (ie == NULL)
  		return got_error_path(relpath, GOT_ERR_FILE_STATUS);
  
  	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path,
  	    relpath)== -1)
  		return got_error_from_errno("asprintf");
  
  	switch (status) {
  	case GOT_STATUS_ADD:
  	case GOT_STATUS_MODIFY:
  		/* XXX could sb.st_mode be passed in by our caller? */
  		if (lstat(ondisk_path, &sb) == -1) {
  			err = got_error_from_errno2("lstat", ondisk_path);
  			break;
  		}
  		if (a->patch_cb) {
  			if (status == GOT_STATUS_ADD) {
  				int choice = GOT_PATCH_CHOICE_NONE;
  				err = (*a->patch_cb)(&choice, a->patch_arg,
  				    status, ie->path, NULL, 1, 1);
  				if (err)
  					break;
  				if (choice != GOT_PATCH_CHOICE_YES)
  					break;
  			} else {
  				err = create_patched_content(&path_content, 0,
  				    staged_blob_id ? staged_blob_id : blob_id,
  				    ondisk_path, dirfd, de_name, ie->path,
  				    a->repo, a->patch_cb, a->patch_arg);
  				if (err || path_content == NULL)
  					break;
  			}
  		}
  		err = got_object_blob_create(&new_staged_blob_id,
  		    path_content ? path_content : ondisk_path, a->repo);
  		if (err)
  			break;
  		memcpy(ie->staged_blob_sha1, new_staged_blob_id->sha1,
  		    SHA1_DIGEST_LENGTH);
  		if (status == GOT_STATUS_ADD || staged_status == GOT_STATUS_ADD)
  			stage = GOT_FILEIDX_STAGE_ADD;
  		else
  			stage = GOT_FILEIDX_STAGE_MODIFY;
  		got_fileindex_entry_stage_set(ie, stage);
  		if (S_ISLNK(sb.st_mode)) {
  			int is_bad_symlink = 0;
  			if (!a->allow_bad_symlinks) {
  				char target_path[PATH_MAX];
  				ssize_t target_len;
  				target_len = readlink(ondisk_path, target_path,
  				    sizeof(target_path));
  				if (target_len == -1) {
  					err = got_error_from_errno2("readlink",
  					    ondisk_path);
  					break;
  				}
  				err = is_bad_symlink_target(&is_bad_symlink,
  				    target_path, target_len, ondisk_path,
  				    a->worktree->root_path);
  				if (err)
  					break;
  				if (is_bad_symlink) {
  					err = got_error_path(ondisk_path,
  					    GOT_ERR_BAD_SYMLINK);
  					break;
  				}
  			}
  			if (is_bad_symlink)
  				got_fileindex_entry_staged_filetype_set(ie,
  				    GOT_FILEIDX_MODE_BAD_SYMLINK);
  			else
  				got_fileindex_entry_staged_filetype_set(ie,
  				    GOT_FILEIDX_MODE_SYMLINK);
  		} else {
  			got_fileindex_entry_staged_filetype_set(ie,
  			    GOT_FILEIDX_MODE_REGULAR_FILE);
  		}
  		a->staged_something = 1;
  		if (a->status_cb == NULL)
  			break;
  		err = (*a->status_cb)(a->status_arg, GOT_STATUS_NO_CHANGE,
  		    get_staged_status(ie), relpath, blob_id,
  		    new_staged_blob_id, NULL, dirfd, de_name);
  		if (err)
  			break;
  		/*
  		 * When staging the reverse of the staged diff,
  		 * implicitly unstage the file.
  		 */
  		if (memcmp(ie->staged_blob_sha1, ie->blob_sha1,
  		    sizeof(ie->blob_sha1)) == 0) {
  			got_fileindex_entry_stage_set(ie,
  			    GOT_FILEIDX_STAGE_NONE);
  		}
  		break;
  	case GOT_STATUS_DELETE:
  		if (staged_status == GOT_STATUS_DELETE)
  			break;
  		if (a->patch_cb) {
  			int choice = GOT_PATCH_CHOICE_NONE;
  			err = (*a->patch_cb)(&choice, a->patch_arg, status,
  			    ie->path, NULL, 1, 1);
  			if (err)
  				break;
  			if (choice == GOT_PATCH_CHOICE_NO)
  				break;
  			if (choice != GOT_PATCH_CHOICE_YES) {
  				err = got_error(GOT_ERR_PATCH_CHOICE);
  				break;
  			}
  		}
  		stage = GOT_FILEIDX_STAGE_DELETE;
  		got_fileindex_entry_stage_set(ie, stage);
  		a->staged_something = 1;
  		if (a->status_cb == NULL)
  			break;
  		err = (*a->status_cb)(a->status_arg, GOT_STATUS_NO_CHANGE,
  		    get_staged_status(ie), relpath, NULL, NULL, NULL, dirfd,
  		    de_name);
  		break;
  	case GOT_STATUS_NO_CHANGE:
  		break;
  	case GOT_STATUS_CONFLICT:
  		err = got_error_path(relpath, GOT_ERR_STAGE_CONFLICT);
  		break;
  	case GOT_STATUS_NONEXISTENT:
  		err = got_error_set_errno(ENOENT, relpath);
  		break;
  	default:
  		err = got_error_path(relpath, GOT_ERR_FILE_STATUS);
  		break;
  	}
  
  	if (path_content && unlink(path_content) == -1 && err == NULL)
  		err = got_error_from_errno2("unlink", path_content);
  	free(path_content);
  	free(ondisk_path);
  	free(new_staged_blob_id);
  	return err;
  }
  
  const struct got_error *
  got_worktree_stage(struct got_worktree *worktree,
      struct got_pathlist_head *paths,
      got_worktree_status_cb status_cb, void *status_arg,
      got_worktree_patch_cb patch_cb, void *patch_arg,
      int allow_bad_symlinks, struct got_repository *repo)
  {
  	const struct got_error *err = NULL, *sync_err, *unlockerr;
  	struct got_pathlist_entry *pe;
  	struct got_fileindex *fileindex = NULL;
  	char *fileindex_path = NULL;
  	struct got_reference *head_ref = NULL;
  	struct got_object_id *head_commit_id = NULL;
  	struct check_stage_ok_arg oka;
  	struct stage_path_arg spa;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = got_ref_open(&head_ref, repo,
  	    got_worktree_get_head_ref_name(worktree), 0);
  	if (err)
  		goto done;
  	err = got_ref_resolve(&head_commit_id, repo, head_ref);
  	if (err)
  		goto done;
  	err = open_fileindex(&fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	/* Check pre-conditions before staging anything. */
  	oka.head_commit_id = head_commit_id;
  	oka.worktree = worktree;
  	oka.fileindex = fileindex;
  	oka.repo = repo;
  	oka.have_changes = 0;
  	TAILQ_FOREACH(pe, paths, entry) {
  		err = worktree_status(worktree, pe->path, fileindex, repo,
  		    check_stage_ok, &oka, NULL, NULL, 1, 0);
  		if (err)
  			goto done;
  	}
  	if (!oka.have_changes) {
  		err = got_error(GOT_ERR_STAGE_NO_CHANGE);
  		goto done;
  	}
  
  	spa.worktree = worktree;
  	spa.fileindex = fileindex;
  	spa.repo = repo;
  	spa.patch_cb = patch_cb;
  	spa.patch_arg = patch_arg;
  	spa.status_cb = status_cb;
  	spa.status_arg = status_arg;
  	spa.staged_something = 0;
  	spa.allow_bad_symlinks = allow_bad_symlinks;
  	TAILQ_FOREACH(pe, paths, entry) {
  		err = worktree_status(worktree, pe->path, fileindex, repo,
  		    stage_path, &spa, NULL, NULL, 1, 0);
  		if (err)
  			goto done;
  	}
  	if (!spa.staged_something) {
  		err = got_error(GOT_ERR_STAGE_NO_CHANGE);
  		goto done;
  	}
  
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	if (head_ref)
  		got_ref_close(head_ref);
  	free(head_commit_id);
  	free(fileindex_path);
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  struct unstage_path_arg {
  	struct got_worktree *worktree;
  	struct got_fileindex *fileindex;
  	struct got_repository *repo;
  	got_worktree_checkout_cb progress_cb;
  	void *progress_arg;
  	got_worktree_patch_cb patch_cb;
  	void *patch_arg;
  };
  
  static const struct got_error *
  create_unstaged_content(char **path_unstaged_content,
      char **path_new_staged_content, struct got_object_id *blob_id,
      struct got_object_id *staged_blob_id, const char *relpath,
      struct got_repository *repo,
      got_worktree_patch_cb patch_cb, void *patch_arg)
  {
  	const struct got_error *err, *free_err;
  	struct got_blob_object *blob = NULL, *staged_blob = NULL;
  	FILE *f1 = NULL, *f2 = NULL, *outfile = NULL, *rejectfile = NULL;
  	char *path1 = NULL, *path2 = NULL, *label1 = NULL;
  	struct got_diffreg_result *diffreg_result = NULL;
  	int line_cur1 = 1, line_cur2 = 1, n = 0, nchunks_used = 0;
  	int have_content = 0, have_rejected_content = 0, i = 0, nchanges = 0;
  
  	*path_unstaged_content = NULL;
  	*path_new_staged_content = NULL;
  
  	err = got_object_id_str(&label1, blob_id);
  	if (err)
  		return err;
  	err = got_object_open_as_blob(&blob, repo, blob_id, 8192);
  	if (err)
  		goto done;
  
  	err = got_opentemp_named(&path1, &f1, "got-unstage-blob-base");
  	if (err)
  		goto done;
  
  	err = got_object_blob_dump_to_file(NULL, NULL, NULL, f1, blob);
  	if (err)
  		goto done;
  
  	err = got_object_open_as_blob(&staged_blob, repo, staged_blob_id, 8192);
  	if (err)
  		goto done;
  
  	err = got_opentemp_named(&path2, &f2, "got-unstage-blob-staged");
  	if (err)
  		goto done;
  
  	err = got_object_blob_dump_to_file(NULL, NULL, NULL, f2, staged_blob);
  	if (err)
  		goto done;
  
  	err = got_diff_files(&diffreg_result, f1, label1, f2,
  	    path2, 3, 0, 1, NULL);
  	if (err)
  		goto done;
  
  	err = got_opentemp_named(path_unstaged_content, &outfile,
  	    "got-unstaged-content");
  	if (err)
  		goto done;
  	err = got_opentemp_named(path_new_staged_content, &rejectfile,
  	    "got-new-staged-content");
  	if (err)
  		goto done;
  
  	if (fseek(f1, 0L, SEEK_SET) == -1) {
  		err = got_ferror(f1, GOT_ERR_IO);
  		goto done;
  	}
  	if (fseek(f2, 0L, SEEK_SET) == -1) {
  		err = got_ferror(f2, GOT_ERR_IO);
  		goto done;
  	}
  	/* Count the number of actual changes in the diff result. */
  	for (n = 0; n < diffreg_result->result->chunks.len; n += nchunks_used) {
  		struct diff_chunk_context cc = {}; 
  		diff_chunk_context_load_change(&cc, &nchunks_used,
  		    diffreg_result->result, n, 0);
  		nchanges++;
  	}
  	for (n = 0; n < diffreg_result->result->chunks.len; n += nchunks_used) {
  		int choice;
  		err = apply_or_reject_change(&choice, &nchunks_used,
  		    diffreg_result->result, n, relpath, f1, f2,
  		    &line_cur1, &line_cur2,
  		    outfile, rejectfile, ++i, nchanges, patch_cb, patch_arg);
  		if (err)
  			goto done;
  		if (choice == GOT_PATCH_CHOICE_YES)
  			have_content = 1;
  		else
  			have_rejected_content = 1;
  		if (choice == GOT_PATCH_CHOICE_QUIT)
  			break;
  	}
  	if (have_content || have_rejected_content)
  		err = copy_remaining_content(f1, f2, &line_cur1, &line_cur2,
  		    outfile, rejectfile);
  done:
  	free(label1);
  	if (blob)
  		got_object_blob_close(blob);
  	if (staged_blob)
  		got_object_blob_close(staged_blob);
  	free_err = got_diffreg_result_free(diffreg_result);
  	if (free_err && err == NULL)
  		err = free_err;
  	if (f1 && fclose(f1) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", path1);
  	if (f2 && fclose(f2) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", path2);
  	if (outfile && fclose(outfile) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", *path_unstaged_content);
  	if (rejectfile && fclose(rejectfile) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", *path_new_staged_content);
  	if (path1 && unlink(path1) == -1 && err == NULL)
  		err = got_error_from_errno2("unlink", path1);
  	if (path2 && unlink(path2) == -1 && err == NULL)
  		err = got_error_from_errno2("unlink", path2);
  	if (err || !have_content) {
  		if (*path_unstaged_content &&
  		    unlink(*path_unstaged_content) == -1 && err == NULL)
  			err = got_error_from_errno2("unlink",
  			    *path_unstaged_content);
  		free(*path_unstaged_content);
  		*path_unstaged_content = NULL;
  	}
  	if (err || !have_content || !have_rejected_content) {
  		if (*path_new_staged_content &&
  		    unlink(*path_new_staged_content) == -1 && err == NULL)
  			err = got_error_from_errno2("unlink",
  			    *path_new_staged_content);
  		free(*path_new_staged_content);
  		*path_new_staged_content = NULL;
  	}
  	free(path1);
  	free(path2);
  	return err;
  }
  
  static const struct got_error *
  unstage_hunks(struct got_object_id *staged_blob_id,
      struct got_blob_object *blob_base,
      struct got_object_id *blob_id, struct got_fileindex_entry *ie,
      const char *ondisk_path, const char *label_orig,
      struct got_worktree *worktree, struct got_repository *repo,
      got_worktree_patch_cb patch_cb, void *patch_arg,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	const struct got_error *err = NULL;
  	char *path_unstaged_content = NULL;
  	char *path_new_staged_content = NULL;
  	char *parent = NULL, *base_path = NULL;
  	char *blob_base_path = NULL;
  	struct got_object_id *new_staged_blob_id = NULL;
  	FILE *f = NULL, *f_base = NULL, *f_deriv2 = NULL;
  	struct stat sb;
  
  	err = create_unstaged_content(&path_unstaged_content,
  	    &path_new_staged_content, blob_id, staged_blob_id,
  	    ie->path, repo, patch_cb, patch_arg);
  	if (err)
  		return err;
  
  	if (path_unstaged_content == NULL)
  		return NULL;
  
  	if (path_new_staged_content) {
  		err = got_object_blob_create(&new_staged_blob_id,
  		    path_new_staged_content, repo);
  		if (err)
  			goto done;
  	}
  
  	f = fopen(path_unstaged_content, "re");
  	if (f == NULL) {
  		err = got_error_from_errno2("fopen",
  		    path_unstaged_content);
  		goto done;
  	}
  	if (fstat(fileno(f), &sb) == -1) {
  		err = got_error_from_errno2("fstat", path_unstaged_content);
  		goto done;
  	}
  	if (got_fileindex_entry_staged_filetype_get(ie) ==
  	    GOT_FILEIDX_MODE_SYMLINK && sb.st_size < PATH_MAX) {
  		char link_target[PATH_MAX];
  		size_t r;
  		r = fread(link_target, 1, sizeof(link_target), f);
  		if (r == 0 && ferror(f)) {
  			err = got_error_from_errno("fread");
  			goto done;
  		}
  		if (r >= sizeof(link_target)) { /* should not happen */
  			err = got_error(GOT_ERR_NO_SPACE);
  			goto done;
  		}
  		link_target[r] = '\0';
  		err = merge_symlink(worktree, blob_base,
  		    ondisk_path, ie->path, label_orig, link_target,
  		    worktree->base_commit_id, repo, progress_cb,
  		    progress_arg);
  	} else {
  		int local_changes_subsumed;
  
  		err = got_path_dirname(&parent, ondisk_path);
  		if (err)
  			return err;
  
  		if (asprintf(&base_path, "%s/got-unstage-blob-orig",
  		    parent) == -1) {
  			err = got_error_from_errno("asprintf");
  			base_path = NULL;
  			goto done;
  		}
  
  		err = got_opentemp_named(&blob_base_path, &f_base, base_path);
  		if (err)
  			goto done;
  		err = got_object_blob_dump_to_file(NULL, NULL, NULL, f_base,
  		    blob_base);
  		if (err)
  			goto done;
  
  		/* 
  		 * In order the run a 3-way merge with a symlink we copy the symlink's
  		 * target path into a temporary file and use that file with diff3.
  		 */
  		if (S_ISLNK(got_fileindex_perms_to_st(ie))) {
  			err = dump_symlink_target_path_to_file(&f_deriv2,
  			    ondisk_path);
  			if (err)
  				goto done;
  		} else {
  			int fd;
  			fd = open(ondisk_path,
  			    O_RDONLY | O_NOFOLLOW | O_CLOEXEC);
  			if (fd == -1) {
  				err = got_error_from_errno2("open", ondisk_path);
  				goto done;
  			}
  			f_deriv2 = fdopen(fd, "r");
  			if (f_deriv2 == NULL) {
  				err = got_error_from_errno2("fdopen", ondisk_path);
  				close(fd);
  				goto done;
  			}
  		}
  
  		err = merge_file(&local_changes_subsumed, worktree,
  		    f_base, f, f_deriv2, ondisk_path, ie->path,
  		    got_fileindex_perms_to_st(ie),
  		    label_orig, "unstaged", NULL, GOT_DIFF_ALGORITHM_MYERS,
  		    repo, progress_cb, progress_arg);
  	}
  	if (err)
  		goto done;
  
  	if (new_staged_blob_id) {
  		memcpy(ie->staged_blob_sha1, new_staged_blob_id->sha1,
  		    SHA1_DIGEST_LENGTH);
  	} else {
  		got_fileindex_entry_stage_set(ie, GOT_FILEIDX_STAGE_NONE);
  		got_fileindex_entry_staged_filetype_set(ie, 0);
  	}
  done:
  	free(new_staged_blob_id);
  	if (path_unstaged_content &&
  	    unlink(path_unstaged_content) == -1 && err == NULL)
  		err = got_error_from_errno2("unlink", path_unstaged_content);
  	if (path_new_staged_content &&
  	    unlink(path_new_staged_content) == -1 && err == NULL)
  		err = got_error_from_errno2("unlink", path_new_staged_content);
  	if (blob_base_path && unlink(blob_base_path) == -1 && err == NULL)
  		err = got_error_from_errno2("unlink", blob_base_path);
  	if (f_base && fclose(f_base) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", path_unstaged_content);
  	if (f && fclose(f) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", path_unstaged_content);
  	if (f_deriv2 && fclose(f_deriv2) == EOF && err == NULL)
  		err = got_error_from_errno2("fclose", ondisk_path);
  	free(path_unstaged_content);
  	free(path_new_staged_content);
  	free(blob_base_path);
  	free(parent);
  	free(base_path);
  	return err;
  }
  
  static const struct got_error *
  unstage_path(void *arg, unsigned char status,
      unsigned char staged_status, const char *relpath,
      struct got_object_id *blob_id, struct got_object_id *staged_blob_id,
      struct got_object_id *commit_id, int dirfd, const char *de_name)
  {
  	const struct got_error *err = NULL;
  	struct unstage_path_arg *a = arg;
  	struct got_fileindex_entry *ie;
  	struct got_blob_object *blob_base = NULL, *blob_staged = NULL;
  	char *ondisk_path = NULL;
  	char *id_str = NULL, *label_orig = NULL;
  	int local_changes_subsumed;
  	struct stat sb;
  
  	if (staged_status != GOT_STATUS_ADD &&
  	    staged_status != GOT_STATUS_MODIFY &&
  	    staged_status != GOT_STATUS_DELETE)
  		return NULL;
  
  	ie = got_fileindex_entry_get(a->fileindex, relpath, strlen(relpath));
  	if (ie == NULL)
  		return got_error_path(relpath, GOT_ERR_FILE_STATUS);
  
  	if (asprintf(&ondisk_path, "%s/%s", a->worktree->root_path, relpath)
  	    == -1)
  		return got_error_from_errno("asprintf");
  
  	err = got_object_id_str(&id_str,
  	    commit_id ? commit_id : a->worktree->base_commit_id);
  	if (err)
  		goto done;
  	if (asprintf(&label_orig, "%s: commit %s", GOT_MERGE_LABEL_BASE,
  	    id_str) == -1) {
  		err = got_error_from_errno("asprintf");
  		goto done;
  	}
  
  	switch (staged_status) {
  	case GOT_STATUS_MODIFY:
  		err = got_object_open_as_blob(&blob_base, a->repo,
  		    blob_id, 8192);
  		if (err)
  			break;
  		/* fall through */
  	case GOT_STATUS_ADD:
  		if (a->patch_cb) {
  			if (staged_status == GOT_STATUS_ADD) {
  				int choice = GOT_PATCH_CHOICE_NONE;
  				err = (*a->patch_cb)(&choice, a->patch_arg,
  				    staged_status, ie->path, NULL, 1, 1);
  				if (err)
  					break;
  				if (choice != GOT_PATCH_CHOICE_YES)
  					break;
  			} else {
  				err = unstage_hunks(staged_blob_id,
  				    blob_base, blob_id, ie, ondisk_path,
  				    label_orig, a->worktree, a->repo,
  				    a->patch_cb, a->patch_arg,
  				    a->progress_cb, a->progress_arg);
  				break; /* Done with this file. */
  			}
  		}
  		err = got_object_open_as_blob(&blob_staged, a->repo,
  		    staged_blob_id, 8192);
  		if (err)
  			break;
  		switch (got_fileindex_entry_staged_filetype_get(ie)) {
  		case GOT_FILEIDX_MODE_BAD_SYMLINK:
  		case GOT_FILEIDX_MODE_REGULAR_FILE:
  			err = merge_blob(&local_changes_subsumed, a->worktree,
  			    blob_base, ondisk_path, relpath,
  			    got_fileindex_perms_to_st(ie), label_orig,
  			    blob_staged, commit_id ? commit_id :
  			    a->worktree->base_commit_id, a->repo,
  			    a->progress_cb, a->progress_arg);
  			break;
  		case GOT_FILEIDX_MODE_SYMLINK:
  			if (S_ISLNK(got_fileindex_perms_to_st(ie))) {
  				char *staged_target;
  				err = got_object_blob_read_to_str(
  				    &staged_target, blob_staged);
  				if (err)
  					goto done;
  				err = merge_symlink(a->worktree, blob_base,
  				    ondisk_path, relpath, label_orig,
  				    staged_target, commit_id ? commit_id :
  				    a->worktree->base_commit_id,
  				    a->repo, a->progress_cb, a->progress_arg);
  				free(staged_target);
  			} else {
  				err = merge_blob(&local_changes_subsumed,
  				    a->worktree, blob_base, ondisk_path,
  				    relpath, got_fileindex_perms_to_st(ie),
  				    label_orig, blob_staged,
  				    commit_id ? commit_id :
  				    a->worktree->base_commit_id, a->repo,
  				    a->progress_cb, a->progress_arg);
  			}
  			break;
  		default:
  			err = got_error_path(relpath, GOT_ERR_BAD_FILETYPE);
  			break;
  		}
  		if (err == NULL) {
  			got_fileindex_entry_stage_set(ie,
  			    GOT_FILEIDX_STAGE_NONE);
  			got_fileindex_entry_staged_filetype_set(ie, 0);
  		}
  		break;
  	case GOT_STATUS_DELETE:
  		if (a->patch_cb) {
  			int choice = GOT_PATCH_CHOICE_NONE;
  			err = (*a->patch_cb)(&choice, a->patch_arg,
  			    staged_status, ie->path, NULL, 1, 1);
  			if (err)
  				break;
  			if (choice == GOT_PATCH_CHOICE_NO)
  				break;
  			if (choice != GOT_PATCH_CHOICE_YES) {
  				err = got_error(GOT_ERR_PATCH_CHOICE);
  				break;
  			}
  		}
  		got_fileindex_entry_stage_set(ie, GOT_FILEIDX_STAGE_NONE);
  		got_fileindex_entry_staged_filetype_set(ie, 0);
  		err = get_file_status(&status, &sb, ie, ondisk_path,
  		    dirfd, de_name, a->repo);
  		if (err)
  			break;
  		err = (*a->progress_cb)(a->progress_arg, status, relpath);
  		break;
  	}
  done:
  	free(ondisk_path);
  	if (blob_base)
  		got_object_blob_close(blob_base);
  	if (blob_staged)
  		got_object_blob_close(blob_staged);
  	free(id_str);
  	free(label_orig);
  	return err;
  }
  
  const struct got_error *
  got_worktree_unstage(struct got_worktree *worktree,
      struct got_pathlist_head *paths,
      got_worktree_checkout_cb progress_cb, void *progress_arg,
      got_worktree_patch_cb patch_cb, void *patch_arg,
      struct got_repository *repo)
  {
  	const struct got_error *err = NULL, *sync_err, *unlockerr;
  	struct got_pathlist_entry *pe;
  	struct got_fileindex *fileindex = NULL;
  	char *fileindex_path = NULL;
  	struct unstage_path_arg upa;
  
  	err = lock_worktree(worktree, LOCK_EX);
  	if (err)
  		return err;
  
  	err = open_fileindex(&fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	upa.worktree = worktree;
  	upa.fileindex = fileindex;
  	upa.repo = repo;
  	upa.progress_cb = progress_cb;
  	upa.progress_arg = progress_arg;
  	upa.patch_cb = patch_cb;
  	upa.patch_arg = patch_arg;
  	TAILQ_FOREACH(pe, paths, entry) {
  		err = worktree_status(worktree, pe->path, fileindex, repo,
  		    unstage_path, &upa, NULL, NULL, 1, 0);
  		if (err)
  			goto done;
  	}
  
  	sync_err = sync_fileindex(fileindex, fileindex_path);
  	if (sync_err && err == NULL)
  		err = sync_err;
  done:
  	free(fileindex_path);
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	unlockerr = lock_worktree(worktree, LOCK_SH);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  struct report_file_info_arg {
  	struct got_worktree *worktree;
  	got_worktree_path_info_cb info_cb;
  	void *info_arg;
  	struct got_pathlist_head *paths;
  	got_cancel_cb cancel_cb;
  	void *cancel_arg;
  };
  
  static const struct got_error *
  report_file_info(void *arg, struct got_fileindex_entry *ie)
  {
  	struct report_file_info_arg *a = arg;
  	struct got_pathlist_entry *pe;
  	struct got_object_id blob_id, staged_blob_id, commit_id;
  	struct got_object_id *blob_idp = NULL, *staged_blob_idp = NULL;
  	struct got_object_id *commit_idp = NULL;
  	int stage;
  
  	if (a->cancel_cb && a->cancel_cb(a->cancel_arg))
  		return got_error(GOT_ERR_CANCELLED);
  
  	TAILQ_FOREACH(pe, a->paths, entry) {
  		if (pe->path_len == 0 || strcmp(pe->path, ie->path) == 0 ||
  		    got_path_is_child(ie->path, pe->path, pe->path_len))
  			break;
  	}
  	if (pe == NULL) /* not found */
  		return NULL;
  
  	if (got_fileindex_entry_has_blob(ie)) {
  		memcpy(blob_id.sha1, ie->blob_sha1, SHA1_DIGEST_LENGTH);
  		blob_idp = &blob_id;
  	}
  	stage = got_fileindex_entry_stage_get(ie);
  	if (stage == GOT_FILEIDX_STAGE_MODIFY ||
  	    stage == GOT_FILEIDX_STAGE_ADD) {
  		memcpy(staged_blob_id.sha1, ie->staged_blob_sha1,
  		    SHA1_DIGEST_LENGTH);
  		staged_blob_idp = &staged_blob_id;
  	}
  
  	if (got_fileindex_entry_has_commit(ie)) {
  		memcpy(commit_id.sha1, ie->commit_sha1, SHA1_DIGEST_LENGTH);
  		commit_idp = &commit_id;
  	}
  
  	return a->info_cb(a->info_arg, ie->path, got_fileindex_perms_to_st(ie),
  	    (time_t)ie->mtime_sec, blob_idp, staged_blob_idp, commit_idp);
  }
  
  const struct got_error *
  got_worktree_path_info(struct got_worktree *worktree,
      struct got_pathlist_head *paths,
      got_worktree_path_info_cb info_cb, void *info_arg,
      got_cancel_cb cancel_cb, void *cancel_arg)
  
  {
  	const struct got_error *err = NULL, *unlockerr;
  	struct got_fileindex *fileindex = NULL;
  	char *fileindex_path = NULL;
  	struct report_file_info_arg arg;
  
  	err = lock_worktree(worktree, LOCK_SH);
  	if (err)
  		return err;
  
  	err = open_fileindex(&fileindex, &fileindex_path, worktree);
  	if (err)
  		goto done;
  
  	arg.worktree = worktree;
  	arg.info_cb = info_cb;
  	arg.info_arg = info_arg;
  	arg.paths = paths;
  	arg.cancel_cb = cancel_cb;
  	arg.cancel_arg = cancel_arg;
  	err = got_fileindex_for_each_entry_safe(fileindex, report_file_info,
  	    &arg);
  done:
  	free(fileindex_path);
  	if (fileindex)
  		got_fileindex_free(fileindex);
  	unlockerr = lock_worktree(worktree, LOCK_UN);
  	if (unlockerr && err == NULL)
  		err = unlockerr;
  	return err;
  }
  
  static const struct got_error *
  patch_check_path(const char *p, char **path, unsigned char *status,
      unsigned char *staged_status, struct got_fileindex *fileindex,
      struct got_worktree *worktree, struct got_repository *repo)
  {
  	const struct got_error *err;
  	struct got_fileindex_entry *ie;
  	struct stat sb;
  	char *ondisk_path = NULL;
  
  	err = got_worktree_resolve_path(path, worktree, p);
  	if (err)
  		return err;
  
  	if (asprintf(&ondisk_path, "%s%s%s", worktree->root_path,
  	    *path[0] ? "/" : "", *path) == -1)
  		return got_error_from_errno("asprintf");
  
  	ie = got_fileindex_entry_get(fileindex, *path, strlen(*path));
  	if (ie) {
  		*staged_status = get_staged_status(ie);
  		err = get_file_status(status, &sb, ie, ondisk_path, -1, NULL,
  		    repo);
  		if (err)
  			goto done;
  	} else {
  		*staged_status = GOT_STATUS_NO_CHANGE;
  		*status = GOT_STATUS_UNVERSIONED;
  		if (lstat(ondisk_path, &sb) == -1) {
  			if (errno != ENOENT) {
  				err = got_error_from_errno2("lstat",
  				    ondisk_path);
  				goto done;
  			}
  			*status = GOT_STATUS_NONEXISTENT;
  		}
  	}
  
  done:
  	free(ondisk_path);
  	return err;
  }
  
  static const struct got_error *
  patch_can_rm(const char *path, unsigned char status,
      unsigned char staged_status)
  {
  	if (status == GOT_STATUS_NONEXISTENT)
  		return got_error_set_errno(ENOENT, path);
  	if (status != GOT_STATUS_NO_CHANGE &&
  	    status != GOT_STATUS_ADD &&
  	    status != GOT_STATUS_MODIFY &&
  	    status != GOT_STATUS_MODE_CHANGE)
  		return got_error_path(path, GOT_ERR_FILE_STATUS);
  	if (staged_status == GOT_STATUS_DELETE)
  		return got_error_path(path, GOT_ERR_FILE_STATUS);
  	return NULL;
  }
  
  static const struct got_error *
  patch_can_add(const char *path, unsigned char status)
  {
  	if (status != GOT_STATUS_NONEXISTENT)
  		return got_error_path(path, GOT_ERR_FILE_STATUS);
  	return NULL;
  }
  
  static const struct got_error *
  patch_can_edit(const char *path, unsigned char status,
      unsigned char staged_status)
  {
  	if (status == GOT_STATUS_NONEXISTENT)
  		return got_error_set_errno(ENOENT, path);
  	if (status != GOT_STATUS_NO_CHANGE &&
  	    status != GOT_STATUS_ADD &&
  	    status != GOT_STATUS_MODIFY)
  		return got_error_path(path, GOT_ERR_FILE_STATUS);
  	if (staged_status == GOT_STATUS_DELETE)
  		return got_error_path(path, GOT_ERR_FILE_STATUS);
  	return NULL;
  }
  
  const struct got_error *
  got_worktree_patch_prepare(struct got_fileindex **fileindex,
      char **fileindex_path, struct got_worktree *worktree)
  {
  	return open_fileindex(fileindex, fileindex_path, worktree);
  }
  
  const struct got_error *
  got_worktree_patch_check_path(const char *old, const char *new,
      char **oldpath, char **newpath, struct got_worktree *worktree,
      struct got_repository *repo, struct got_fileindex *fileindex)
  {
  	const struct got_error *err = NULL;
  	int file_renamed = 0;
  	unsigned char status_old, staged_status_old;
  	unsigned char status_new, staged_status_new;
  
  	*oldpath = NULL;
  	*newpath = NULL;
  
  	err = patch_check_path(old != NULL ? old : new, oldpath,
  	    &status_old, &staged_status_old, fileindex, worktree, repo);
  	if (err)
  		goto done;
  
  	err = patch_check_path(new != NULL ? new : old, newpath,
  	    &status_new, &staged_status_new, fileindex, worktree, repo);
  	if (err)
  		goto done;
  
  	if (old != NULL && new != NULL && strcmp(old, new) != 0)
  		file_renamed = 1;
  
  	if (old != NULL && new == NULL)
  		err = patch_can_rm(*oldpath, status_old, staged_status_old);
  	else if (file_renamed) {
  		err = patch_can_rm(*oldpath, status_old, staged_status_old);
  		if (err == NULL)
  			err = patch_can_add(*newpath, status_new);
  	} else if (old == NULL)
  		err = patch_can_add(*newpath, status_new);
  	else
  		err = patch_can_edit(*newpath, status_new, staged_status_new);
  
  done:
  	if (err) {
  		free(*oldpath);
  		*oldpath = NULL;
  		free(*newpath);
  		*newpath = NULL;
  	}
  	return err;
  }
  
  const struct got_error *
  got_worktree_patch_schedule_add(const char *path, struct got_repository *repo,
      struct got_worktree *worktree, struct got_fileindex *fileindex,
      got_worktree_checkout_cb progress_cb, void *progress_arg)
  {
  	struct schedule_addition_args saa;
  
  	memset(&saa, 0, sizeof(saa));
  	saa.worktree = worktree;
  	saa.fileindex = fileindex;
  	saa.progress_cb = progress_cb;
  	saa.progress_arg = progress_arg;
  	saa.repo = repo;
  
  	return worktree_status(worktree, path, fileindex, repo,
  	    schedule_addition, &saa, NULL, NULL, 1, 0);
  }
  
  const struct got_error *
  got_worktree_patch_schedule_rm(const char *path, struct got_repository *repo,
      struct got_worktree *worktree, struct got_fileindex *fileindex,
      got_worktree_delete_cb progress_cb, void *progress_arg)
  {
  	struct schedule_deletion_args sda;
  
  	memset(&sda, 0, sizeof(sda));
  	sda.worktree = worktree;
  	sda.fileindex = fileindex;
  	sda.progress_cb = progress_cb;
  	sda.progress_arg = progress_arg;
  	sda.repo = repo;
  	sda.delete_local_mods = 0;
  	sda.keep_on_disk = 0;
  	sda.ignore_missing_paths = 0;
  	sda.status_codes = NULL;
  
  	return worktree_status(worktree, path, fileindex, repo,
  	    schedule_for_deletion, &sda, NULL, NULL, 1, 1);
  }
  
  const struct got_error *
  got_worktree_patch_complete(struct got_fileindex *fileindex,
      const char *fileindex_path)
  {
  	const struct got_error *err = NULL;
  
  	err = sync_fileindex(fileindex, fileindex_path);
  	got_fileindex_free(fileindex);
  
  	return err;
  }