short circuit out of a few places where we would allocate zero bytes

diff --git a/commit.c b/commit.c
index e867b86e6a10d64354226b04f71df98d7448e072..edd4dedcdd13c2c3fd02714ef282b173f7cec7fe 100644 (file)
--- a/commit.c
+++ b/commit.c
@@ -560,6 +560,9 @@ void sort_in_topological_order(struct commit_list ** list)
                next = next->next;
                count++;
        }
+       
+       if (!count)
+               return;
        /* allocate an array to help sort the list */
        nodes = xcalloc(count, sizeof(*nodes));
        /* link the list to the array */