commit: avoid parent list buildup in clear_commit_marks_many()

clear_commit_marks_1() clears the marks of the first parent and its
first parent and so on, and saves the higher numbered parents in a list
for later.  There is no benefit in keeping that list growing with each
handled commit.  Clear it after each run to reduce peak memory usage.

Signed-off-by: René Scharfe <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: rscharfe

commit.c

@@ -780,14 +780,14 @@ static void clear_commit_marks_1(struct commit_list **plist,
 
 void clear_commit_marks_many(size_t nr, struct commit **commit, unsigned int mark)
 {
-	struct commit_list *list = NULL;
-
 	for (size_t i = 0; i < nr; i++) {
+		struct commit_list *list = NULL;
+
 		clear_commit_marks_1(&list, *commit, mark);
+		while (list)
+			clear_commit_marks_1(&list, pop_commit(&list), mark);
 		commit++;
 	}
-	while (list)
-		clear_commit_marks_1(&list, pop_commit(&list), mark);
 }
 
 void clear_commit_marks(struct commit *commit, unsigned int mark)