thodg/libgit2/src/reset.c

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• Hash : bfe7d7de
  Author :
  Date : 2012-11-26T17:24:02
  

  Reorder operations in git reset
  
  This corrects the order of operations in git reset so that the
  checkout to reset the working directory content is done before
  the HEAD is moved.  This allows us to use the HEAD and the index
  content to know what files can / should safely be reset.
  
  Unfortunately, there are still some cases where the behavior of
  this revision differs from core git.  Notable, a file which has
  been added to the index but is not present in the HEAD is
  considered to be tracked by core git (and thus removable by a
  reset command) whereas since this loads the target state into
  the index prior to resetting, it will consider such a file to be
  untracked and won't touch it.  That is a larger fix that I'll
  defer to a future commit.
  

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• src/reset.c

• /*
   * Copyright (C) 2009-2012 the libgit2 contributors
   *
   * 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 "commit.h"
  #include "tag.h"
  #include "merge.h"
  #include "git2/reset.h"
  #include "git2/checkout.h"
  #include "git2/merge.h"
  
  #define ERROR_MSG "Cannot perform reset"
  
  static int update_head(git_repository *repo, git_object *commit)
  {
  	int error;
  	git_reference *head = NULL, *target = NULL;
  
  	error = git_repository_head(&head, repo);
  
  	if (error < 0 && error != GIT_EORPHANEDHEAD)
  		return error;
  
  	if (error == GIT_EORPHANEDHEAD) {
  		giterr_clear();
  
  		/*
  		 * TODO: This is a bit weak as this doesn't support chained
  		 * symbolic references. yet.
  		 */
  		if ((error = git_reference_lookup(&head, repo, GIT_HEAD_FILE)) < 0)
  			goto cleanup;
  
  		if ((error = git_reference_create(
  			&target,
  			repo,
  			git_reference_symbolic_target(head),
  			git_object_id(commit), 0)) < 0)
  				goto cleanup;
  	} else {
  		if ((error = git_reference_set_target(head, git_object_id(commit))) < 0)
  			goto cleanup;
  	}
  
  	error = 0;
  
  cleanup:
  	git_reference_free(head);
  	git_reference_free(target);
  	return error;
  }
  
  int git_reset(
  	git_repository *repo,
  	git_object *target,
  	git_reset_t reset_type)
  {
  	git_object *commit = NULL;
  	git_index *index = NULL;
  	git_tree *tree = NULL;
  	int error = 0;
  	git_checkout_opts opts = GIT_CHECKOUT_OPTS_INIT;
  
  	assert(repo && target);
  
  	if (git_object_owner(target) != repo) {
  		giterr_set(GITERR_OBJECT,
  			"%s - The given target does not belong to this repository.", ERROR_MSG);
  		return -1;
  	}
  
  	if (reset_type != GIT_RESET_SOFT &&
  		(error = git_repository__ensure_not_bare(repo,
  			reset_type == GIT_RESET_MIXED ? "reset mixed" : "reset hard")) < 0)
  		return error;
  
  	if ((error = git_object_peel(&commit, target, GIT_OBJ_COMMIT)) < 0 ||
  		(error = git_repository_index(&index, repo)) < 0 ||
  		(error = git_commit_tree(&tree, (git_commit *)commit)) < 0)
  		goto cleanup;
  
  	if (reset_type == GIT_RESET_SOFT &&
  		(git_repository_state(repo) == GIT_REPOSITORY_STATE_MERGE ||
  		 git_index_has_conflicts(index)))
  	{
  		giterr_set(GITERR_OBJECT, "%s (soft) in the middle of a merge.", ERROR_MSG);
  		error = GIT_EUNMERGED;
  		goto cleanup;
  	}
  
  	/* move HEAD to the new target */
  	if ((error = update_head(repo, commit)) < 0)
  		goto cleanup;
  
  	if (reset_type == GIT_RESET_HARD) {
  		/* overwrite working directory with HEAD */
  		opts.checkout_strategy = GIT_CHECKOUT_FORCE;
  
  		if ((error = git_checkout_tree(repo, (git_object *)tree, &opts)) < 0)
  			goto cleanup;
  	}
  
  	if (reset_type > GIT_RESET_SOFT) {
  		/* reset index to the target content */
  
  		if ((error = git_repository_index(&index, repo)) < 0 ||
  			(error = git_index_read_tree(index, tree)) < 0 ||
  			(error = git_index_write(index)) < 0)
  			goto cleanup;
  
  		if ((error = git_repository_merge_cleanup(repo)) < 0) {
  			giterr_set(GITERR_INDEX, "%s - failed to clean up merge data", ERROR_MSG);
  			goto cleanup;
  		}
  	}
  
  cleanup:
  	git_object_free(commit);
  	git_index_free(index);
  	git_tree_free(tree);
  
  	return error;
  }
  

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