Merge pull request libgit2#6539 from cavaquinho/fix/revwalk-insert-by-date

Partial fix for libgit2#6532: insert-by-date order.

Author: ethomson

src/libgit2/commit_list.c

@@ -43,13 +43,18 @@ int git_commit_list_time_cmp(const void *a, const void *b)
 	return 0;
 }
 
-git_commit_list *git_commit_list_insert(git_commit_list_node *item, git_commit_list **list_p)
-{
+git_commit_list *git_commit_list_create(git_commit_list_node *item, git_commit_list *next) {
 	git_commit_list *new_list = git__malloc(sizeof(git_commit_list));
 	if (new_list != NULL) {
 		new_list->item = item;
-		new_list->next = *list_p;
+		new_list->next = next;
 	}
+	return new_list;
+}
+
+git_commit_list *git_commit_list_insert(git_commit_list_node *item, git_commit_list **list_p)
+{
+	git_commit_list *new_list = git_commit_list_create(item, *list_p);
 	*list_p = new_list;
 	return new_list;
 }

src/libgit2/commit_list.h

@@ -49,6 +49,7 @@ git_commit_list_node *git_commit_list_alloc_node(git_revwalk *walk);
 int git_commit_list_generation_cmp(const void *a, const void *b);
 int git_commit_list_time_cmp(const void *a, const void *b);
 void git_commit_list_free(git_commit_list **list_p);
+git_commit_list *git_commit_list_create(git_commit_list_node *item, git_commit_list *next);
 git_commit_list *git_commit_list_insert(git_commit_list_node *item, git_commit_list **list_p);
 git_commit_list *git_commit_list_insert_by_date(git_commit_list_node *item, git_commit_list **list_p);
 int git_commit_list_parse(git_revwalk *walk, git_commit_list_node *commit);

src/libgit2/revwalk.c

@@ -83,8 +83,13 @@ int git_revwalk__push_commit(git_revwalk *walk, const git_oid *oid, const git_re
 
 	commit->uninteresting = opts->uninteresting;
 	list = walk->user_input;
-	if ((opts->insert_by_date &&
-	    git_commit_list_insert_by_date(commit, &list) == NULL) ||
+
+	/* To insert by date, we need to parse so we know the date. */
+	if (opts->insert_by_date && ((error = git_commit_list_parse(walk, commit)) < 0))
+		return error;
+
+	if ((opts->insert_by_date == 0 ||
+	    git_commit_list_insert_by_date(commit, &list) == NULL) &&
 	    git_commit_list_insert(commit, &list) == NULL) {
 		git_error_set_oom();
 		return -1;
@@ -609,7 +614,7 @@ static int sort_in_topological_order(git_commit_list **out, git_revwalk *walk, g
 static int prepare_walk(git_revwalk *walk)
 {
 	int error = 0;
-	git_commit_list *list, *commits = NULL;
+	git_commit_list *list, *commits = NULL, *commits_last = NULL;
 	git_commit_list_node *next;
 
 	/* If there were no pushes, we know that the walk is already over */
@@ -618,6 +623,12 @@ static int prepare_walk(git_revwalk *walk)
 		return GIT_ITEROVER;
 	}
 
+	/* 
+	 * This is a bit convoluted, but necessary to maintain the order of
+	 * the commits. This is especially important in situations where
+	 * git_revwalk__push_glob is called with a git_revwalk__push_options
+	 * setting insert_by_date = 1, which is critical for fetch negotiation.
+	 */
 	for (list = walk->user_input; list; list = list->next) {
 		git_commit_list_node *commit = list->item;
 		if ((error = git_commit_list_parse(walk, commit)) < 0)
@@ -627,8 +638,19 @@ static int prepare_walk(git_revwalk *walk)
 			mark_parents_uninteresting(commit);
 
 		if (!commit->seen) {
+			git_commit_list *new_list = NULL;
+			if ((new_list = git_commit_list_create(commit, NULL)) == NULL) {
+				git_error_set_oom();
+				return -1;
+			}
+			
 			commit->seen = 1;
-			git_commit_list_insert(commit, &commits);
+			if (commits_last == NULL)
+				commits = new_list;
+			else
+				commits_last->next = new_list;
+			
+			commits_last = new_list;
 		}
 	}