thodg/libgit2/src/libgit2/stash.c

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• Hash : ef4ab298
  Author :
  Date : 2021-11-14T08:47:40
  

  refactor: `src` is now `src/libgit2`

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• src/libgit2/stash.c

• /*
   * Copyright (C) the libgit2 contributors. All rights reserved.
   *
   * This file is part of libgit2, distributed under the GNU GPL v2 with
   * a Linking Exception. For full terms see the included COPYING file.
   */
  
  #include "common.h"
  
  #include "repository.h"
  #include "commit.h"
  #include "tree.h"
  #include "reflog.h"
  #include "blob.h"
  #include "git2/diff.h"
  #include "git2/stash.h"
  #include "git2/status.h"
  #include "git2/checkout.h"
  #include "git2/index.h"
  #include "git2/transaction.h"
  #include "git2/merge.h"
  #include "index.h"
  #include "signature.h"
  #include "iterator.h"
  #include "merge.h"
  #include "diff.h"
  #include "diff_generate.h"
  
  static int create_error(int error, const char *msg)
  {
  	git_error_set(GIT_ERROR_STASH, "cannot stash changes - %s", msg);
  	return error;
  }
  
  static int retrieve_head(git_reference **out, git_repository *repo)
  {
  	int error = git_repository_head(out, repo);
  
  	if (error == GIT_EUNBORNBRANCH)
  		return create_error(error, "you do not have the initial commit yet.");
  
  	return error;
  }
  
  static int append_abbreviated_oid(git_str *out, const git_oid *b_commit)
  {
  	char *formatted_oid;
  
  	formatted_oid = git_oid_allocfmt(b_commit);
  	GIT_ERROR_CHECK_ALLOC(formatted_oid);
  
  	git_str_put(out, formatted_oid, 7);
  	git__free(formatted_oid);
  
  	return git_str_oom(out) ? -1 : 0;
  }
  
  static int append_commit_description(git_str *out, git_commit *commit)
  {
  	const char *summary = git_commit_summary(commit);
  	GIT_ERROR_CHECK_ALLOC(summary);
  
  	if (append_abbreviated_oid(out, git_commit_id(commit)) < 0)
  		return -1;
  
  	git_str_putc(out, ' ');
  	git_str_puts(out, summary);
  	git_str_putc(out, '\n');
  
  	return git_str_oom(out) ? -1 : 0;
  }
  
  static int retrieve_base_commit_and_message(
  	git_commit **b_commit,
  	git_str *stash_message,
  	git_repository *repo)
  {
  	git_reference *head = NULL;
  	int error;
  
  	if ((error = retrieve_head(&head, repo)) < 0)
  		return error;
  
  	if (strcmp("HEAD", git_reference_name(head)) == 0)
  		error = git_str_puts(stash_message, "(no branch): ");
  	else
  		error = git_str_printf(
  			stash_message,
  			"%s: ",
  			git_reference_name(head) + strlen(GIT_REFS_HEADS_DIR));
  	if (error < 0)
  		goto cleanup;
  
  	if ((error = git_commit_lookup(
  			 b_commit, repo, git_reference_target(head))) < 0)
  		goto cleanup;
  
  	if ((error = append_commit_description(stash_message, *b_commit)) < 0)
  		goto cleanup;
  
  cleanup:
  	git_reference_free(head);
  	return error;
  }
  
  static int build_tree_from_index(
  	git_tree **out,
  	git_repository *repo,
  	git_index *index)
  {
  	int error;
  	git_oid i_tree_oid;
  
  	if ((error = git_index_write_tree_to(&i_tree_oid, index, repo)) < 0)
  		return error;
  
  	return git_tree_lookup(out, repo, &i_tree_oid);
  }
  
  static int commit_index(
  	git_commit **i_commit,
  	git_repository *repo,
  	git_index *index,
  	const git_signature *stasher,
  	const char *message,
  	const git_commit *parent)
  {
  	git_tree *i_tree = NULL;
  	git_oid i_commit_oid;
  	git_str msg = GIT_STR_INIT;
  	int error;
  
  	if ((error = build_tree_from_index(&i_tree, repo, index)) < 0)
  		goto cleanup;
  
  	if ((error = git_str_printf(&msg, "index on %s\n", message)) < 0)
  		goto cleanup;
  
  	if ((error = git_commit_create(
  		&i_commit_oid,
  		git_index_owner(index),
  		NULL,
  		stasher,
  		stasher,
  		NULL,
  		git_str_cstr(&msg),
  		i_tree,
  		1,
  		&parent)) < 0)
  		goto cleanup;
  
  	error = git_commit_lookup(i_commit, git_index_owner(index), &i_commit_oid);
  
  cleanup:
  	git_tree_free(i_tree);
  	git_str_dispose(&msg);
  	return error;
  }
  
  struct stash_update_rules {
  	bool include_changed;
  	bool include_untracked;
  	bool include_ignored;
  };
  
  /*
   * Similar to git_index_add_bypath but able to operate on any
   * index without making assumptions about the repository's index
   */
  static int stash_to_index(
  	git_repository *repo,
  	git_index *index,
  	const char *path)
  {
  	git_index *repo_index = NULL;
  	git_index_entry entry = {{0}};
  	struct stat st;
  	int error;
  
  	if (!git_repository_is_bare(repo) &&
  	    (error = git_repository_index__weakptr(&repo_index, repo)) < 0)
  		return error;
  
  	if ((error = git_blob__create_from_paths(
  	    &entry.id, &st, repo, NULL, path, 0, true)) < 0)
  		return error;
  
  	git_index_entry__init_from_stat(&entry, &st,
  		(repo_index == NULL || !repo_index->distrust_filemode));
  
  	entry.path = path;
  
  	return git_index_add(index, &entry);
  }
  
  static int stash_update_index_from_diff(
  	git_repository *repo,
  	git_index *index,
  	const git_diff *diff,
  	struct stash_update_rules *data)
  {
  	int error = 0;
  	size_t d, max_d = git_diff_num_deltas(diff);
  
  	for (d = 0; !error && d < max_d; ++d) {
  		const char *add_path = NULL;
  		const git_diff_delta *delta = git_diff_get_delta(diff, d);
  
  		switch (delta->status) {
  		case GIT_DELTA_IGNORED:
  			if (data->include_ignored)
  				add_path = delta->new_file.path;
  			break;
  
  		case GIT_DELTA_UNTRACKED:
  			if (data->include_untracked &&
  				delta->new_file.mode != GIT_FILEMODE_TREE)
  				add_path = delta->new_file.path;
  			break;
  
  		case GIT_DELTA_ADDED:
  		case GIT_DELTA_MODIFIED:
  			if (data->include_changed)
  				add_path = delta->new_file.path;
  			break;
  
  		case GIT_DELTA_DELETED:
  			if (data->include_changed &&
  				!git_index_find(NULL, index, delta->old_file.path))
  				error = git_index_remove(index, delta->old_file.path, 0);
  			break;
  
  		default:
  			/* Unimplemented */
  			git_error_set(
  				GIT_ERROR_INVALID,
  				"cannot update index. Unimplemented status (%d)",
  				delta->status);
  			return -1;
  		}
  
  		if (add_path != NULL)
  			error = stash_to_index(repo, index, add_path);
  	}
  
  	return error;
  }
  
  static int build_untracked_tree(
  	git_tree **tree_out,
  	git_repository *repo,
  	git_commit *i_commit,
  	uint32_t flags)
  {
  	git_index *i_index = NULL;
  	git_tree *i_tree = NULL;
  	git_diff *diff = NULL;
  	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
  	struct stash_update_rules data = {0};
  	int error;
  
  	if ((error = git_index_new(&i_index)) < 0)
  		goto cleanup;
  
  	if (flags & GIT_STASH_INCLUDE_UNTRACKED) {
  		opts.flags |= GIT_DIFF_INCLUDE_UNTRACKED |
  			GIT_DIFF_RECURSE_UNTRACKED_DIRS;
  		data.include_untracked = true;
  	}
  
  	if (flags & GIT_STASH_INCLUDE_IGNORED) {
  		opts.flags |= GIT_DIFF_INCLUDE_IGNORED |
  			GIT_DIFF_RECURSE_IGNORED_DIRS;
  		data.include_ignored = true;
  	}
  
  	if ((error = git_commit_tree(&i_tree, i_commit)) < 0)
  		goto cleanup;
  
  	if ((error = git_diff_tree_to_workdir(&diff, repo, i_tree, &opts)) < 0)
  		goto cleanup;
  
  	if ((error = stash_update_index_from_diff(repo, i_index, diff, &data)) < 0)
  		goto cleanup;
  
  	error = build_tree_from_index(tree_out, repo, i_index);
  
  cleanup:
  	git_diff_free(diff);
  	git_tree_free(i_tree);
  	git_index_free(i_index);
  	return error;
  }
  
  static int commit_untracked(
  	git_commit **u_commit,
  	git_repository *repo,
  	const git_signature *stasher,
  	const char *message,
  	git_commit *i_commit,
  	uint32_t flags)
  {
  	git_tree *u_tree = NULL;
  	git_oid u_commit_oid;
  	git_str msg = GIT_STR_INIT;
  	int error;
  
  	if ((error = build_untracked_tree(&u_tree, repo, i_commit, flags)) < 0)
  		goto cleanup;
  
  	if ((error = git_str_printf(&msg, "untracked files on %s\n", message)) < 0)
  		goto cleanup;
  
  	if ((error = git_commit_create(
  		&u_commit_oid,
  		repo,
  		NULL,
  		stasher,
  		stasher,
  		NULL,
  		git_str_cstr(&msg),
  		u_tree,
  		0,
  		NULL)) < 0)
  		goto cleanup;
  
  	error = git_commit_lookup(u_commit, repo, &u_commit_oid);
  
  cleanup:
  	git_tree_free(u_tree);
  	git_str_dispose(&msg);
  	return error;
  }
  
  static git_diff_delta *stash_delta_merge(
  	const git_diff_delta *a,
  	const git_diff_delta *b,
  	git_pool *pool)
  {
  	/* Special case for stash: if a file is deleted in the index, but exists
  	 * in the working tree, we need to stash the workdir copy for the workdir.
  	 */
  	if (a->status == GIT_DELTA_DELETED && b->status == GIT_DELTA_UNTRACKED) {
  		git_diff_delta *dup = git_diff__delta_dup(b, pool);
  
  		if (dup)
  			dup->status = GIT_DELTA_MODIFIED;
  		return dup;
  	}
  
  	return git_diff__merge_like_cgit(a, b, pool);
  }
  
  static int build_workdir_tree(
  	git_tree **tree_out,
  	git_repository *repo,
  	git_index *i_index,
  	git_commit *b_commit)
  {
  	git_tree *b_tree = NULL;
  	git_diff *diff = NULL, *idx_to_wd = NULL;
  	git_diff_options opts = GIT_DIFF_OPTIONS_INIT;
  	struct stash_update_rules data = {0};
  	int error;
  
  	opts.flags = GIT_DIFF_IGNORE_SUBMODULES | GIT_DIFF_INCLUDE_UNTRACKED;
  
  	if ((error = git_commit_tree(&b_tree, b_commit)) < 0)
  		goto cleanup;
  
  	if ((error = git_diff_tree_to_index(&diff, repo, b_tree, i_index, &opts)) < 0 ||
  		(error = git_diff_index_to_workdir(&idx_to_wd, repo, i_index, &opts)) < 0 ||
  		(error = git_diff__merge(diff, idx_to_wd, stash_delta_merge)) < 0)
  		goto cleanup;
  
  	data.include_changed = true;
  
  	if ((error = stash_update_index_from_diff(repo, i_index, diff, &data)) < 0)
  		goto cleanup;
  
  	error = build_tree_from_index(tree_out, repo, i_index);
  
  cleanup:
  	git_diff_free(idx_to_wd);
  	git_diff_free(diff);
  	git_tree_free(b_tree);
  
  	return error;
  }
  
  static int commit_worktree(
  	git_oid *w_commit_oid,
  	git_repository *repo,
  	const git_signature *stasher,
  	const char *message,
  	git_commit *i_commit,
  	git_commit *b_commit,
  	git_commit *u_commit)
  {
  	const git_commit *parents[] = {	NULL, NULL, NULL };
  	git_index *i_index = NULL, *r_index = NULL;
  	git_tree *w_tree = NULL;
  	int error = 0, ignorecase;
  
  	parents[0] = b_commit;
  	parents[1] = i_commit;
  	parents[2] = u_commit;
  
  	if ((error = git_repository_index(&r_index, repo) < 0) ||
  	    (error = git_index_new(&i_index)) < 0 ||
  	    (error = git_index__fill(i_index, &r_index->entries) < 0) ||
  	    (error = git_repository__configmap_lookup(&ignorecase, repo, GIT_CONFIGMAP_IGNORECASE)) < 0)
  		goto cleanup;
  
  	git_index__set_ignore_case(i_index, ignorecase);
  
  	if ((error = build_workdir_tree(&w_tree, repo, i_index, b_commit)) < 0)
  		goto cleanup;
  
  	error = git_commit_create(
  		w_commit_oid,
  		repo,
  		NULL,
  		stasher,
  		stasher,
  		NULL,
  		message,
  		w_tree,
  		u_commit ? 3 : 2,
  		parents);
  
  cleanup:
  	git_tree_free(w_tree);
  	git_index_free(i_index);
  	git_index_free(r_index);
  	return error;
  }
  
  static int prepare_worktree_commit_message(git_str *out, const char *user_message)
  {
  	git_str buf = GIT_STR_INIT;
  	int error = 0;
  
  	if (!user_message) {
  		git_str_printf(&buf, "WIP on %s", git_str_cstr(out));
  	} else {
  		const char *colon;
  
  		if ((colon = strchr(git_str_cstr(out), ':')) == NULL)
  			goto cleanup;
  
  		git_str_puts(&buf, "On ");
  		git_str_put(&buf, git_str_cstr(out), colon - out->ptr);
  		git_str_printf(&buf, ": %s\n", user_message);
  	}
  
  	if (git_str_oom(&buf)) {
  		error = -1;
  		goto cleanup;
  	}
  
  	git_str_swap(out, &buf);
  
  cleanup:
  	git_str_dispose(&buf);
  	return error;
  }
  
  static int update_reflog(
  	git_oid *w_commit_oid,
  	git_repository *repo,
  	const char *message)
  {
  	git_reference *stash;
  	int error;
  
  	if ((error = git_reference_ensure_log(repo, GIT_REFS_STASH_FILE)) < 0)
  		return error;
  
  	error = git_reference_create(&stash, repo, GIT_REFS_STASH_FILE, w_commit_oid, 1, message);
  
  	git_reference_free(stash);
  
  	return error;
  }
  
  static int is_dirty_cb(const char *path, unsigned int status, void *payload)
  {
  	GIT_UNUSED(path);
  	GIT_UNUSED(status);
  	GIT_UNUSED(payload);
  
  	return GIT_PASSTHROUGH;
  }
  
  static int ensure_there_are_changes_to_stash(git_repository *repo, uint32_t flags)
  {
  	int error;
  	git_status_options opts = GIT_STATUS_OPTIONS_INIT;
  
  	opts.show  = GIT_STATUS_SHOW_INDEX_AND_WORKDIR;
  	opts.flags = GIT_STATUS_OPT_EXCLUDE_SUBMODULES;
  
  	if (flags & GIT_STASH_INCLUDE_UNTRACKED)
  		opts.flags |= GIT_STATUS_OPT_INCLUDE_UNTRACKED |
  			GIT_STATUS_OPT_RECURSE_UNTRACKED_DIRS;
  
  	if (flags & GIT_STASH_INCLUDE_IGNORED)
  		opts.flags |= GIT_STATUS_OPT_INCLUDE_IGNORED |
  			GIT_STATUS_OPT_RECURSE_IGNORED_DIRS;
  
  	error = git_status_foreach_ext(repo, &opts, is_dirty_cb, NULL);
  
  	if (error == GIT_PASSTHROUGH)
  		return 0;
  
  	if (!error)
  		return create_error(GIT_ENOTFOUND, "there is nothing to stash.");
  
  	return error;
  }
  
  static int reset_index_and_workdir(git_repository *repo, git_commit *commit, uint32_t flags)
  {
  	git_checkout_options opts = GIT_CHECKOUT_OPTIONS_INIT;
  
  	opts.checkout_strategy = GIT_CHECKOUT_FORCE;
  	if (flags & GIT_STASH_INCLUDE_UNTRACKED)
  		opts.checkout_strategy |= GIT_CHECKOUT_REMOVE_UNTRACKED;
  	if (flags & GIT_STASH_INCLUDE_IGNORED)
  		opts.checkout_strategy |= GIT_CHECKOUT_REMOVE_IGNORED;
  
  	return git_checkout_tree(repo, (git_object *)commit, &opts);
  }
  
  int git_stash_save(
  	git_oid *out,
  	git_repository *repo,
  	const git_signature *stasher,
  	const char *message,
  	uint32_t flags)
  {
  	git_index *index = NULL;
  	git_commit *b_commit = NULL, *i_commit = NULL, *u_commit = NULL;
  	git_str msg = GIT_STR_INIT;
  	int error;
  
  	GIT_ASSERT_ARG(out);
  	GIT_ASSERT_ARG(repo);
  	GIT_ASSERT_ARG(stasher);
  
  	if ((error = git_repository__ensure_not_bare(repo, "stash save")) < 0)
  		return error;
  
  	if ((error = retrieve_base_commit_and_message(&b_commit, &msg, repo)) < 0)
  		goto cleanup;
  
  	if ((error = ensure_there_are_changes_to_stash(repo, flags)) < 0)
  		goto cleanup;
  
  	if ((error = git_repository_index(&index, repo)) < 0)
  		goto cleanup;
  
  	if ((error = commit_index(&i_commit, repo, index, stasher,
  				  git_str_cstr(&msg), b_commit)) < 0)
  		goto cleanup;
  
  	if ((flags & (GIT_STASH_INCLUDE_UNTRACKED | GIT_STASH_INCLUDE_IGNORED)) &&
  	    (error = commit_untracked(&u_commit, repo, stasher,
  				      git_str_cstr(&msg), i_commit, flags)) < 0)
  		goto cleanup;
  
  	if ((error = prepare_worktree_commit_message(&msg, message)) < 0)
  		goto cleanup;
  
  	if ((error = commit_worktree(out, repo, stasher, git_str_cstr(&msg),
  				     i_commit, b_commit, u_commit)) < 0)
  		goto cleanup;
  
  	git_str_rtrim(&msg);
  
  	if ((error = update_reflog(out, repo, git_str_cstr(&msg))) < 0)
  		goto cleanup;
  
  	if ((error = reset_index_and_workdir(repo, (flags & GIT_STASH_KEEP_INDEX) ? i_commit : b_commit,
  					     flags)) < 0)
  		goto cleanup;
  
  cleanup:
  
  	git_str_dispose(&msg);
  	git_commit_free(i_commit);
  	git_commit_free(b_commit);
  	git_commit_free(u_commit);
  	git_index_free(index);
  
  	return error;
  }
  
  static int retrieve_stash_commit(
  	git_commit **commit,
  	git_repository *repo,
  	size_t index)
  {
  	git_reference *stash = NULL;
  	git_reflog *reflog = NULL;
  	int error;
  	size_t max;
  	const git_reflog_entry *entry;
  
  	if ((error = git_reference_lookup(&stash, repo, GIT_REFS_STASH_FILE)) < 0)
  		goto cleanup;
  
  	if ((error = git_reflog_read(&reflog, repo, GIT_REFS_STASH_FILE)) < 0)
  		goto cleanup;
  
  	max = git_reflog_entrycount(reflog);
  	if (!max || index > max - 1) {
  		error = GIT_ENOTFOUND;
  		git_error_set(GIT_ERROR_STASH, "no stashed state at position %" PRIuZ, index);
  		goto cleanup;
  	}
  
  	entry = git_reflog_entry_byindex(reflog, index);
  	if ((error = git_commit_lookup(commit, repo, git_reflog_entry_id_new(entry))) < 0)
  		goto cleanup;
  
  cleanup:
  	git_reference_free(stash);
  	git_reflog_free(reflog);
  	return error;
  }
  
  static int retrieve_stash_trees(
  	git_tree **out_stash_tree,
  	git_tree **out_base_tree,
  	git_tree **out_index_tree,
  	git_tree **out_index_parent_tree,
  	git_tree **out_untracked_tree,
  	git_commit *stash_commit)
  {
  	git_tree *stash_tree = NULL;
  	git_commit *base_commit = NULL;
  	git_tree *base_tree = NULL;
  	git_commit *index_commit = NULL;
  	git_tree *index_tree = NULL;
  	git_commit *index_parent_commit = NULL;
  	git_tree *index_parent_tree = NULL;
  	git_commit *untracked_commit = NULL;
  	git_tree *untracked_tree = NULL;
  	int error;
  
  	if ((error = git_commit_tree(&stash_tree, stash_commit)) < 0)
  		goto cleanup;
  
  	if ((error = git_commit_parent(&base_commit, stash_commit, 0)) < 0)
  		goto cleanup;
  	if ((error = git_commit_tree(&base_tree, base_commit)) < 0)
  		goto cleanup;
  
  	if ((error = git_commit_parent(&index_commit, stash_commit, 1)) < 0)
  		goto cleanup;
  	if ((error = git_commit_tree(&index_tree, index_commit)) < 0)
  		goto cleanup;
  
  	if ((error = git_commit_parent(&index_parent_commit, index_commit, 0)) < 0)
  		goto cleanup;
  	if ((error = git_commit_tree(&index_parent_tree, index_parent_commit)) < 0)
  		goto cleanup;
  
  	if (git_commit_parentcount(stash_commit) == 3) {
  		if ((error = git_commit_parent(&untracked_commit, stash_commit, 2)) < 0)
  			goto cleanup;
  		if ((error = git_commit_tree(&untracked_tree, untracked_commit)) < 0)
  			goto cleanup;
  	}
  
  	*out_stash_tree = stash_tree;
  	*out_base_tree = base_tree;
  	*out_index_tree = index_tree;
  	*out_index_parent_tree = index_parent_tree;
  	*out_untracked_tree = untracked_tree;
  
  cleanup:
  	git_commit_free(untracked_commit);
  	git_commit_free(index_parent_commit);
  	git_commit_free(index_commit);
  	git_commit_free(base_commit);
  	if (error < 0) {
  		git_tree_free(stash_tree);
  		git_tree_free(base_tree);
  		git_tree_free(index_tree);
  		git_tree_free(index_parent_tree);
  		git_tree_free(untracked_tree);
  	}
  	return error;
  }
  
  static int merge_indexes(
  	git_index **out,
  	git_repository *repo,
  	git_tree *ancestor_tree,
  	git_index *ours_index,
  	git_index *theirs_index)
  {
  	git_iterator *ancestor = NULL, *ours = NULL, *theirs = NULL;
  	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
  	int error;
  
  	iter_opts.flags = GIT_ITERATOR_DONT_IGNORE_CASE;
  
  	if ((error = git_iterator_for_tree(&ancestor, ancestor_tree, &iter_opts)) < 0 ||
  		(error = git_iterator_for_index(&ours, repo, ours_index, &iter_opts)) < 0 ||
  		(error = git_iterator_for_index(&theirs, repo, theirs_index, &iter_opts)) < 0)
  		goto done;
  
  	error = git_merge__iterators(out, repo, ancestor, ours, theirs, NULL);
  
  done:
  	git_iterator_free(ancestor);
  	git_iterator_free(ours);
  	git_iterator_free(theirs);
  	return error;
  }
  
  static int merge_index_and_tree(
  	git_index **out,
  	git_repository *repo,
  	git_tree *ancestor_tree,
  	git_index *ours_index,
  	git_tree *theirs_tree)
  {
  	git_iterator *ancestor = NULL, *ours = NULL, *theirs = NULL;
  	git_iterator_options iter_opts = GIT_ITERATOR_OPTIONS_INIT;
  	int error;
  
  	iter_opts.flags = GIT_ITERATOR_DONT_IGNORE_CASE;
  
  	if ((error = git_iterator_for_tree(&ancestor, ancestor_tree, &iter_opts)) < 0 ||
  		(error = git_iterator_for_index(&ours, repo, ours_index, &iter_opts)) < 0 ||
  		(error = git_iterator_for_tree(&theirs, theirs_tree, &iter_opts)) < 0)
  		goto done;
  
  	error = git_merge__iterators(out, repo, ancestor, ours, theirs, NULL);
  
  done:
  	git_iterator_free(ancestor);
  	git_iterator_free(ours);
  	git_iterator_free(theirs);
  	return error;
  }
  
  static void normalize_apply_options(
  	git_stash_apply_options *opts,
  	const git_stash_apply_options *given_apply_opts)
  {
  	if (given_apply_opts != NULL) {
  		memcpy(opts, given_apply_opts, sizeof(git_stash_apply_options));
  	} else {
  		git_stash_apply_options default_apply_opts = GIT_STASH_APPLY_OPTIONS_INIT;
  		memcpy(opts, &default_apply_opts, sizeof(git_stash_apply_options));
  	}
  
  	opts->checkout_options.checkout_strategy |= GIT_CHECKOUT_NO_REFRESH;
  
  	if (!opts->checkout_options.our_label)
  		opts->checkout_options.our_label = "Updated upstream";
  
  	if (!opts->checkout_options.their_label)
  		opts->checkout_options.their_label = "Stashed changes";
  }
  
  int git_stash_apply_options_init(git_stash_apply_options *opts, unsigned int version)
  {
  	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
  		opts, version, git_stash_apply_options, GIT_STASH_APPLY_OPTIONS_INIT);
  	return 0;
  }
  
  #ifndef GIT_DEPRECATE_HARD
  int git_stash_apply_init_options(git_stash_apply_options *opts, unsigned int version)
  {
  	return git_stash_apply_options_init(opts, version);
  }
  #endif
  
  #define NOTIFY_PROGRESS(opts, progress_type)				\
  	do {								\
  		if ((opts).progress_cb &&				\
  		    (error = (opts).progress_cb((progress_type), (opts).progress_payload))) { \
  			error = (error < 0) ? error : -1;		\
  			goto cleanup;					\
  		}							\
  	} while(false);
  
  static int ensure_clean_index(git_repository *repo, git_index *index)
  {
  	git_tree *head_tree = NULL;
  	git_diff *index_diff = NULL;
  	int error = 0;
  
  	if ((error = git_repository_head_tree(&head_tree, repo)) < 0 ||
  		(error = git_diff_tree_to_index(
  			&index_diff, repo, head_tree, index, NULL)) < 0)
  		goto done;
  
  	if (git_diff_num_deltas(index_diff) > 0) {
  		git_error_set(GIT_ERROR_STASH, "%" PRIuZ " uncommitted changes exist in the index",
  			git_diff_num_deltas(index_diff));
  		error = GIT_EUNCOMMITTED;
  	}
  
  done:
  	git_diff_free(index_diff);
  	git_tree_free(head_tree);
  	return error;
  }
  
  static int stage_new_file(const git_index_entry **entries, void *data)
  {
  	git_index *index = data;
  
  	if(entries[0] == NULL)
  		return git_index_add(index, entries[1]);
  	else
  		return git_index_add(index, entries[0]);
  }
  
  static int stage_new_files(
  	git_index **out,
  	git_tree *parent_tree,
  	git_tree *tree)
  {
  	git_iterator *iterators[2] = { NULL, NULL };
  	git_iterator_options iterator_options = GIT_ITERATOR_OPTIONS_INIT;
  	git_index *index = NULL;
  	int error;
  
  	if ((error = git_index_new(&index)) < 0 ||
  		(error = git_iterator_for_tree(
  			&iterators[0], parent_tree, &iterator_options)) < 0 ||
  		(error = git_iterator_for_tree(
  			&iterators[1], tree, &iterator_options)) < 0)
  		goto done;
  
  	error = git_iterator_walk(iterators, 2, stage_new_file, index);
  
  done:
  	if (error < 0)
  		git_index_free(index);
  	else
  		*out = index;
  
  	git_iterator_free(iterators[0]);
  	git_iterator_free(iterators[1]);
  
  	return error;
  }
  
  int git_stash_apply(
  	git_repository *repo,
  	size_t index,
  	const git_stash_apply_options *given_opts)
  {
  	git_stash_apply_options opts;
  	unsigned int checkout_strategy;
  	git_commit *stash_commit = NULL;
  	git_tree *stash_tree = NULL;
  	git_tree *stash_parent_tree = NULL;
  	git_tree *index_tree = NULL;
  	git_tree *index_parent_tree = NULL;
  	git_tree *untracked_tree = NULL;
  	git_index *stash_adds = NULL;
  	git_index *repo_index = NULL;
  	git_index *unstashed_index = NULL;
  	git_index *modified_index = NULL;
  	git_index *untracked_index = NULL;
  	int error;
  
  	GIT_ERROR_CHECK_VERSION(given_opts, GIT_STASH_APPLY_OPTIONS_VERSION, "git_stash_apply_options");
  
  	normalize_apply_options(&opts, given_opts);
  	checkout_strategy = opts.checkout_options.checkout_strategy;
  
  	NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_LOADING_STASH);
  
  	/* Retrieve commit corresponding to the given stash */
  	if ((error = retrieve_stash_commit(&stash_commit, repo, index)) < 0)
  		goto cleanup;
  
  	/* Retrieve all trees in the stash */
  	if ((error = retrieve_stash_trees(
  			&stash_tree, &stash_parent_tree, &index_tree,
  			&index_parent_tree, &untracked_tree, stash_commit)) < 0)
  		goto cleanup;
  
  	/* Load repo index */
  	if ((error = git_repository_index(&repo_index, repo)) < 0)
  		goto cleanup;
  
  	NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_ANALYZE_INDEX);
  
  	if ((error = ensure_clean_index(repo, repo_index)) < 0)
  		goto cleanup;
  
  	/* Restore index if required */
  	if ((opts.flags & GIT_STASH_APPLY_REINSTATE_INDEX) &&
  		git_oid_cmp(git_tree_id(stash_parent_tree), git_tree_id(index_tree))) {
  
  		if ((error = merge_index_and_tree(
  				&unstashed_index, repo, index_parent_tree, repo_index, index_tree)) < 0)
  			goto cleanup;
  
  		if (git_index_has_conflicts(unstashed_index)) {
  			error = GIT_ECONFLICT;
  			goto cleanup;
  		}
  
  	/* Otherwise, stage any new files in the stash tree.  (Note: their
  	 * previously unstaged contents are staged, not the previously staged.)
  	 */
  	} else if ((opts.flags & GIT_STASH_APPLY_REINSTATE_INDEX) == 0) {
  		if ((error = stage_new_files(
  				&stash_adds, stash_parent_tree, stash_tree)) < 0 ||
  			(error = merge_indexes(
  				&unstashed_index, repo, stash_parent_tree, repo_index, stash_adds)) < 0)
  			goto cleanup;
  	}
  
  	NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_ANALYZE_MODIFIED);
  
  	/* Restore modified files in workdir */
  	if ((error = merge_index_and_tree(
  			&modified_index, repo, stash_parent_tree, repo_index, stash_tree)) < 0)
  		goto cleanup;
  
  	/* If applicable, restore untracked / ignored files in workdir */
  	if (untracked_tree) {
  		NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_ANALYZE_UNTRACKED);
  
  		if ((error = merge_index_and_tree(&untracked_index, repo, NULL, repo_index, untracked_tree)) < 0)
  			goto cleanup;
  	}
  
  	if (untracked_index) {
  		opts.checkout_options.checkout_strategy |= GIT_CHECKOUT_DONT_UPDATE_INDEX;
  
  		NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_CHECKOUT_UNTRACKED);
  
  		if ((error = git_checkout_index(repo, untracked_index, &opts.checkout_options)) < 0)
  			goto cleanup;
  
  		opts.checkout_options.checkout_strategy = checkout_strategy;
  	}
  
  
  	/* If there are conflicts in the modified index, then we need to actually
  	 * check that out as the repo's index.  Otherwise, we don't update the
  	 * index.
  	 */
  
  	if (!git_index_has_conflicts(modified_index))
  		opts.checkout_options.checkout_strategy |= GIT_CHECKOUT_DONT_UPDATE_INDEX;
  
  	/* Check out the modified index using the existing repo index as baseline,
  	 * so that existing modifications in the index can be rewritten even when
  	 * checking out safely.
  	 */
  	opts.checkout_options.baseline_index = repo_index;
  
  	NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_CHECKOUT_MODIFIED);
  
  	if ((error = git_checkout_index(repo, modified_index, &opts.checkout_options)) < 0)
  		goto cleanup;
  
  	if (unstashed_index && !git_index_has_conflicts(modified_index)) {
  		if ((error = git_index_read_index(repo_index, unstashed_index)) < 0)
  			goto cleanup;
  	}
  
  	NOTIFY_PROGRESS(opts, GIT_STASH_APPLY_PROGRESS_DONE);
  
  	error = git_index_write(repo_index);
  
  cleanup:
  	git_index_free(untracked_index);
  	git_index_free(modified_index);
  	git_index_free(unstashed_index);
  	git_index_free(stash_adds);
  	git_index_free(repo_index);
  	git_tree_free(untracked_tree);
  	git_tree_free(index_parent_tree);
  	git_tree_free(index_tree);
  	git_tree_free(stash_parent_tree);
  	git_tree_free(stash_tree);
  	git_commit_free(stash_commit);
  	return error;
  }
  
  int git_stash_foreach(
  	git_repository *repo,
  	git_stash_cb callback,
  	void *payload)
  {
  	git_reference *stash;
  	git_reflog *reflog = NULL;
  	int error;
  	size_t i, max;
  	const git_reflog_entry *entry;
  
  	error = git_reference_lookup(&stash, repo, GIT_REFS_STASH_FILE);
  	if (error == GIT_ENOTFOUND) {
  		git_error_clear();
  		return 0;
  	}
  	if (error < 0)
  		goto cleanup;
  
  	if ((error = git_reflog_read(&reflog, repo, GIT_REFS_STASH_FILE)) < 0)
  		goto cleanup;
  
  	max = git_reflog_entrycount(reflog);
  	for (i = 0; i < max; i++) {
  		entry = git_reflog_entry_byindex(reflog, i);
  
  		error = callback(i,
  			git_reflog_entry_message(entry),
  			git_reflog_entry_id_new(entry),
  			payload);
  
  		if (error) {
  			git_error_set_after_callback(error);
  			break;
  		}
  	}
  
  cleanup:
  	git_reference_free(stash);
  	git_reflog_free(reflog);
  	return error;
  }
  
  int git_stash_drop(
  	git_repository *repo,
  	size_t index)
  {
  	git_transaction *tx;
  	git_reference *stash = NULL;
  	git_reflog *reflog = NULL;
  	size_t max;
  	int error;
  
  	if ((error = git_transaction_new(&tx, repo)) < 0)
  		return error;
  
  	if ((error = git_transaction_lock_ref(tx, GIT_REFS_STASH_FILE)) < 0)
  		goto cleanup;
  
  	if ((error = git_reference_lookup(&stash, repo, GIT_REFS_STASH_FILE)) < 0)
  		goto cleanup;
  
  	if ((error = git_reflog_read(&reflog, repo, GIT_REFS_STASH_FILE)) < 0)
  		goto cleanup;
  
  	max = git_reflog_entrycount(reflog);
  
  	if (!max || index > max - 1) {
  		error = GIT_ENOTFOUND;
  		git_error_set(GIT_ERROR_STASH, "no stashed state at position %" PRIuZ, index);
  		goto cleanup;
  	}
  
  	if ((error = git_reflog_drop(reflog, index, true)) < 0)
  		goto cleanup;
  
  	if ((error = git_transaction_set_reflog(tx, GIT_REFS_STASH_FILE, reflog)) < 0)
  		goto cleanup;
  
  	if (max == 1) {
  		if ((error = git_transaction_remove(tx, GIT_REFS_STASH_FILE)) < 0)
  			goto cleanup;
  	} else if (index == 0) {
  		const git_reflog_entry *entry;
  
  		entry = git_reflog_entry_byindex(reflog, 0);
  		if ((error = git_transaction_set_target(tx, GIT_REFS_STASH_FILE, &entry->oid_cur, NULL, NULL)) < 0)
  			goto cleanup;
  	}
  
  	error = git_transaction_commit(tx);
  
  cleanup:
  	git_reference_free(stash);
  	git_transaction_free(tx);
  	git_reflog_free(reflog);
  	return error;
  }
  
  int git_stash_pop(
  	git_repository *repo,
  	size_t index,
  	const git_stash_apply_options *options)
  {
  	int error;
  
  	if ((error = git_stash_apply(repo, index, options)) < 0)
  		return error;
  
  	return git_stash_drop(repo, index);
  }
  

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