Add git_reset()

Currently supports Soft and Mixed modes.

1 files changed, 103 insertions, 0 deletions

diff --git a/src/reset.c b/src/reset.c
new file mode 100644
index 000000000..14f7a236a
--- /dev/null
+++ b/src/reset.c
@@ -0,0 +1,103 @@
+/*
+ * 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 "git2/reset.h"
+
+#define ERROR_MSG "Cannot perform reset"
+
+static int reset_error_invalid(const char *msg)
+{
+	giterr_set(GITERR_INVALID, "%s - %s", ERROR_MSG, msg);
+	return -1;
+}
+
+int git_reset(
+	git_repository *repo,
+	const git_object *target,
+	git_reset_type reset_type)
+{
+	git_otype target_type = GIT_OBJ_BAD;
+	git_object *commit = NULL;
+	git_index *index = NULL;
+	git_tree *tree = NULL;
+	int error = -1;
+
+	assert(repo && target);
+	assert(reset_type == GIT_RESET_SOFT || reset_type == GIT_RESET_MIXED);
+
+	if (git_object_owner(target) != repo)
+		return reset_error_invalid("The given target does not belong to this repository.");
+
+	if (reset_type == GIT_RESET_MIXED && git_repository_is_bare(repo))
+		return reset_error_invalid("Mixed reset is not allowed in a bare repository.");
+
+	target_type = git_object_type(target);
+
+	switch (target_type)
+	{
+	case GIT_OBJ_TAG:
+		if (git_tag_peel(&commit, (git_tag *)target) < 0)
+			goto cleanup;
+
+		if (git_object_type(commit) != GIT_OBJ_COMMIT) {
+			reset_error_invalid("The given target does not resolve to a commit.");
+			goto cleanup;
+		}
+		break;
+
+	case GIT_OBJ_COMMIT:
+		commit = (git_object *)target;
+		break;
+
+	default:
+		return reset_error_invalid("Only git_tag and git_commit objects are valid targets.");
+	}
+
+	//TODO: Check for unmerged entries
+
+	if (git_reference__update(repo, git_object_id(commit), GIT_HEAD_FILE) < 0)
+		goto cleanup;
+
+	if (reset_type == GIT_RESET_SOFT) {
+		error = 0;
+		goto cleanup;
+	}
+
+	if (git_commit_tree(&tree, (git_commit *)commit) < 0) {
+		giterr_set(GITERR_OBJECT, "%s - Failed to retrieve the commit tree.", ERROR_MSG);
+		goto cleanup;
+	}
+
+	if (git_repository_index(&index, repo) < 0) {
+		giterr_set(GITERR_OBJECT, "%s - Failed to retrieve the index.", ERROR_MSG);
+		goto cleanup;
+	}
+
+	if (git_index_read_tree(index, tree) < 0) {
+		giterr_set(GITERR_INDEX, "%s - Failed to update the index.", ERROR_MSG);
+		goto cleanup;
+	}
+
+	if (git_index_write(index) < 0) {
+		giterr_set(GITERR_INDEX, "%s - Failed to write the index.", ERROR_MSG);
+		goto cleanup;
+	}
+
+	error = 0;
+
+cleanup:
+	if (target_type == GIT_OBJ_TAG)
+		git_object_free(commit);
+
+	git_index_free(index);
+	git_tree_free(tree);
+
+	return error;
+}