From 917f85a1a4616a93fcbba30c82caff9c1c011b83 Mon Sep 17 00:00:00 2001
From: Arthur Schreiber <schreiber.arthur@googlemail.com>
Date: Thu, 9 Oct 2014 14:16:10 +0200
Subject: [PATCH] Extract shared functionality.

---
 src/merge.c | 104 +++++++++++++++++++++++-----------------------------
 1 file changed, 45 insertions(+), 59 deletions(-)

diff --git a/src/merge.c b/src/merge.c
index c7ca97c12..8252f6767 100644
--- a/src/merge.c
+++ b/src/merge.c
@@ -62,16 +62,14 @@ struct merge_diff_df_data {
 
 /* Merge base computation */
 
-int git_merge_base_many(git_oid *out, git_repository *repo, size_t length, const git_oid input_array[])
+int merge_bases_many(git_commit_list **out, git_revwalk **walk_out, git_repository *repo, size_t length, const git_oid input_array[])
 {
-	git_revwalk *walk;
+	git_revwalk *walk = NULL;
 	git_vector list;
 	git_commit_list *result = NULL;
+	git_commit_list_node *commit;
 	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);
@@ -82,104 +80,92 @@ int git_merge_base_many(git_oid *out, git_repository *repo, size_t length, const
 		return -1;
 
 	if (git_revwalk_new(&walk, repo) < 0)
-		goto cleanup;
+		goto on_error;
 
 	for (i = 1; i < length; i++) {
 		commit = git_revwalk__commit_lookup(walk, &input_array[i]);
 		if (commit == NULL)
-			goto cleanup;
+			goto on_error;
 
 		git_vector_insert(&list, commit);
 	}
 
 	commit = git_revwalk__commit_lookup(walk, &input_array[0]);
 	if (commit == NULL)
-		goto cleanup;
+		goto on_error;
 
 	if (git_merge__bases_many(&result, walk, commit, &list) < 0)
-		goto cleanup;
+		goto on_error;
 
 	if (!result) {
 		giterr_set(GITERR_MERGE, "No merge base found");
 		error = GIT_ENOTFOUND;
-		goto cleanup;
+		goto on_error;
 	}
 
+	*out = result;
+	*walk_out = walk;
+
+	git_vector_free(&list);
+	return 0;
+
+on_error:
+	git_vector_free(&list);
+	git_revwalk_free(walk);
+	return error;
+}
+
+int git_merge_base_many(git_oid *out, git_repository *repo, size_t length, const git_oid input_array[])
+{
+	git_revwalk *walk;
+	git_commit_list *result = NULL;
+	int error = 0;
+
+	assert(out && repo && input_array);
+
+	if ((error = merge_bases_many(&result, &walk, repo, length, input_array)) < 0)
+		return error;
+
 	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;
+
+	return 0;
 }
 
 int git_merge_bases_many(git_oidarray *out, git_repository *repo, size_t length, const git_oid input_array[])
 {
 	git_revwalk *walk;
-	git_vector list;
-	git_commit_list *current, *result = NULL;
-	int error = -1;
-	unsigned int i;
-	git_commit_list_node *commit;
+	git_commit_list *list, *result = NULL;
+	int error = 0;
 	git_array_oid_t array;
 
 	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) {
-		giterr_set(GITERR_MERGE, "No merge base found");
-		error = GIT_ENOTFOUND;
-		goto cleanup;
-	}
+	if ((error = merge_bases_many(&result, &walk, repo, length, input_array)) < 0)
+		return error;
 
 	git_array_init(array);
 
-	current = result;
-	while (current) {
+	list = result;
+	while (list) {
 		git_oid *id = git_array_alloc(array);
-		if (id == NULL)
+		if (id == NULL) {
+			error = -1;
 			goto cleanup;
+		}
 
-		git_oid_cpy(id, &current->item->oid);
-		current = current->next;
+		git_oid_cpy(id, &list->item->oid);
+		list = list->next;
 	}
 
 	git_oidarray__from_array(out, &array);
 
-	error = 0;
-
 cleanup:
 	git_commit_list_free(&result);
 	git_revwalk_free(walk);
-	git_vector_free(&list);
+
 	return error;
 }