revwalk: return GIT_EREVWALKER earlier if no references were pushed

In the case that walk->one is NULL, we know that we have no positive
references, so we already know that the revwalk is over.

diff --git a/src/revwalk.c b/src/revwalk.c
index a62576038c8412d40a29e7072dc935e7c23eb110..041dc1a1c7b9d3329a9970b1183173f3dd742c8b 100644 (file)
--- a/src/revwalk.c
+++ b/src/revwalk.c
@@ -689,6 +689,13 @@ static int prepare_walk(git_revwalk *walk)
        commit_object *next, *two;
        commit_list *bases = NULL;
 
+       /*
+        * If walk->one is NULL, there were no positive references,
+        * so we know that the walk is already over.
+        */
+       if (walk->one == NULL)
+               return GIT_EREVWALKOVER;
+
        /* first figure out what the merge bases are */
        if (merge_bases_many(&bases, walk, walk->one, &walk->twos) < 0)
                return -1;