1 files changed, 296 insertions, 0 deletions
diff --git a/src/merge.c b/src/merge.c
new file mode 100644
index 000000000..e0010d6a4
--- /dev/null
+++ b/src/merge.c
@@ -0,0 +1,296 @@
+/*
+ * 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 "repository.h"
+#include "revwalk.h"
+#include "buffer.h"
+#include "merge.h"
+#include "refs.h"
+#include "git2/repository.h"
+#include "git2/merge.h"
+#include "git2/reset.h"
+#include "commit_list.h"
+
+int git_repository_merge_cleanup(git_repository *repo)
+{
+	int error = 0;
+	git_buf merge_head_path = GIT_BUF_INIT,
+		merge_mode_path = GIT_BUF_INIT,
+		merge_msg_path = GIT_BUF_INIT;
+
+	assert(repo);
+
+	if (git_buf_joinpath(&merge_head_path, repo->path_repository, GIT_MERGE_HEAD_FILE) < 0 ||
+		git_buf_joinpath(&merge_mode_path, repo->path_repository, GIT_MERGE_MODE_FILE) < 0 ||
+		git_buf_joinpath(&merge_msg_path, repo->path_repository, GIT_MERGE_MSG_FILE) < 0)
+		return -1;
+
+	if (git_path_isfile(merge_head_path.ptr)) {
+		if ((error = p_unlink(merge_head_path.ptr)) < 0)
+			goto cleanup;
+	}
+
+	if (git_path_isfile(merge_mode_path.ptr))
+		(void)p_unlink(merge_mode_path.ptr);
+
+	if (git_path_isfile(merge_msg_path.ptr))
+		(void)p_unlink(merge_msg_path.ptr);
+
+cleanup:
+	git_buf_free(&merge_msg_path);
+	git_buf_free(&merge_mode_path);
+	git_buf_free(&merge_head_path);
+
+	return error;
+}
+
+int git_merge_base_many(git_oid *out, git_repository *repo, const git_oid input_array[], size_t length)
+{
+	git_revwalk *walk;
+	git_vector list;
+	git_commit_list *result = NULL;
+	int error = -1;
+	unsigned int i;
+	git_commit_list_node *commit;
+
+	assert(out && repo && input_array);
+
+	if (length < 2) {
+		giterr_set(GITERR_INVALID, "At least two commits are required to find an ancestor. Provided 'length' was %u.", length);
+		return -1;
+	}
+
+	if (git_vector_init(&list, length - 1, NULL) < 0)
+		return -1;
+
+	if (git_revwalk_new(&walk, repo) < 0)
+		goto cleanup;
+
+	for (i = 1; i < length; i++) {
+		commit = git_revwalk__commit_lookup(walk, &input_array[i]);
+		if (commit == NULL)
+			goto cleanup;
+
+		git_vector_insert(&list, commit);
+	}
+
+	commit = git_revwalk__commit_lookup(walk, &input_array[0]);
+	if (commit == NULL)
+		goto cleanup;
+
+	if (git_merge__bases_many(&result, walk, commit, &list) < 0)
+		goto cleanup;
+
+	if (!result) {
+		error = GIT_ENOTFOUND;
+		goto cleanup;
+	}
+
+	git_oid_cpy(out, &result->item->oid);
+
+	error = 0;
+
+cleanup:
+	git_commit_list_free(&result);
+	git_revwalk_free(walk);
+	git_vector_free(&list);
+	return error;
+}
+
+int git_merge_base(git_oid *out, git_repository *repo, const git_oid *one, const git_oid *two)
+{
+	git_revwalk *walk;
+	git_vector list;
+	git_commit_list *result = NULL;
+	git_commit_list_node *commit;
+	void *contents[1];
+
+	if (git_revwalk_new(&walk, repo) < 0)
+		return -1;
+
+	commit = git_revwalk__commit_lookup(walk, two);
+	if (commit == NULL)
+		goto on_error;
+
+	/* This is just one value, so we can do it on the stack */
+	memset(&list, 0x0, sizeof(git_vector));
+	contents[0] = commit;
+	list.length = 1;
+	list.contents = contents;
+
+	commit = git_revwalk__commit_lookup(walk, one);
+	if (commit == NULL)
+		goto on_error;
+
+	if (git_merge__bases_many(&result, walk, commit, &list) < 0)
+		goto on_error;
+
+	if (!result) {
+		git_revwalk_free(walk);
+		giterr_clear();
+		return GIT_ENOTFOUND;
+	}
+
+	git_oid_cpy(out, &result->item->oid);
+	git_commit_list_free(&result);
+	git_revwalk_free(walk);
+
+	return 0;
+
+on_error:
+	git_revwalk_free(walk);
+	return -1;
+}
+
+static int interesting(git_pqueue *list)
+{
+	unsigned int i;
+	/* element 0 isn't used - we need to start at 1 */
+	for (i = 1; i < list->size; i++) {
+		git_commit_list_node *commit = list->d[i];
+		if ((commit->flags & STALE) == 0)
+			return 1;
+	}
+
+	return 0;
+}
+
+int git_merge__bases_many(git_commit_list **out, git_revwalk *walk, git_commit_list_node *one, git_vector *twos)
+{
+	int error;
+	unsigned int i;
+	git_commit_list_node *two;
+	git_commit_list *result = NULL, *tmp = NULL;
+	git_pqueue list;
+
+	/* if the commit is repeated, we have a our merge base already */
+	git_vector_foreach(twos, i, two) {
+		if (one == two)
+			return git_commit_list_insert(one, out) ? 0 : -1;
+	}
+
+	if (git_pqueue_init(&list, twos->length * 2, git_commit_list_time_cmp) < 0)
+		return -1;
+
+	if (git_commit_list_parse(walk, one) < 0)
+	    return -1;
+
+	one->flags |= PARENT1;
+	if (git_pqueue_insert(&list, one) < 0)
+		return -1;
+
+	git_vector_foreach(twos, i, two) {
+		git_commit_list_parse(walk, two);
+		two->flags |= PARENT2;
+		if (git_pqueue_insert(&list, two) < 0)
+			return -1;
+	}
+
+	/* as long as there are non-STALE commits */
+	while (interesting(&list)) {
+		git_commit_list_node *commit;
+		int flags;
+
+		commit = git_pqueue_pop(&list);
+
+		flags = commit->flags & (PARENT1 | PARENT2 | STALE);
+		if (flags == (PARENT1 | PARENT2)) {
+			if (!(commit->flags & RESULT)) {
+				commit->flags |= RESULT;
+				if (git_commit_list_insert(commit, &result) == NULL)
+					return -1;
+			}
+			/* we mark the parents of a merge stale */
+			flags |= STALE;
+		}
+
+		for (i = 0; i < commit->out_degree; i++) {
+			git_commit_list_node *p = commit->parents[i];
+			if ((p->flags & flags) == flags)
+				continue;
+
+			if ((error = git_commit_list_parse(walk, p)) < 0)
+				return error;
+
+			p->flags |= flags;
+			if (git_pqueue_insert(&list, p) < 0)
+				return -1;
+		}
+	}
+
+	git_pqueue_free(&list);
+
+	/* filter out any stale commits in the results */
+	tmp = result;
+	result = NULL;
+
+	while (tmp) {
+		struct git_commit_list *next = tmp->next;
+		if (!(tmp->item->flags & STALE))
+			if (git_commit_list_insert_by_date(tmp->item, &result) == NULL)
+				return -1;
+
+		git__free(tmp);
+		tmp = next;
+	}
+
+	*out = result;
+	return 0;
+}
+
+int git_repository_mergehead_foreach(git_repository *repo,
+	git_repository_mergehead_foreach_cb cb,
+	void *payload)
+{
+	git_buf merge_head_path = GIT_BUF_INIT, merge_head_file = GIT_BUF_INIT;
+	char *buffer, *line;
+	size_t line_num = 1;
+	git_oid oid;
+	int error = 0;
+
+	assert(repo && cb);
+
+	if ((error = git_buf_joinpath(&merge_head_path, repo->path_repository,
+		GIT_MERGE_HEAD_FILE)) < 0)
+		return error;
+
+	if ((error = git_futils_readbuffer(&merge_head_file,
+		git_buf_cstr(&merge_head_path))) < 0)
+		goto cleanup;
+
+	buffer = merge_head_file.ptr;
+
+	while ((line = git__strsep(&buffer, "\n")) != NULL) {
+		if (strlen(line) != GIT_OID_HEXSZ) {
+			giterr_set(GITERR_INVALID, "Unable to parse OID - invalid length");
+			error = -1;
+			goto cleanup;
+		}
+
+		if ((error = git_oid_fromstr(&oid, line)) < 0)
+			goto cleanup;
+
+		if (cb(&oid, payload) < 0) {
+			error = GIT_EUSER;
+			goto cleanup;
+		}
+
+		++line_num;
+	}
+
+	if (*buffer) {
+		giterr_set(GITERR_MERGE, "No EOL at line %d", line_num);
+		error = -1;
+		goto cleanup;
+	}
+
+cleanup:
+	git_buf_free(&merge_head_path);
+	git_buf_free(&merge_head_file);
+
+	return error;
+}