fast-export: ensure we traverse commits in topological order

diff --git a/http-walker.c b/http-walker.c
index 51c18f2685aa1bdb7e4ed471d0ec5d31c6684fda..9dc6b27b457a2979a95018679a0b885e6fb62d9a 100644 (file)
--- a/http-walker.c
+++ b/http-walker.c
@@ -442,6 +442,8 @@ static int setup_index(struct walker *walker, struct alt_base *repo, unsigned ch
                return -1;
 
        new_pack = parse_pack_index(sha1);
+       if (!new_pack)
+               return -1; /* parse_pack_index() already issued error message */
        new_pack->next = repo->packs;
        repo->packs = new_pack;
        return 0;