git-p4: Unset P4DIFF environment variable when using 'p4 -du diff'

diff --git a/builtin-fmt-merge-msg.c b/builtin-fmt-merge-msg.c
index 6163bd4975e3e361e36ffc89ea4c91d0edd02949..ebb3f37cf158dc479f364111893279805fa9a230 100644 (file)
--- a/builtin-fmt-merge-msg.c
+++ b/builtin-fmt-merge-msg.c
@@ -187,7 +187,8 @@ static void shortlog(const char *name, unsigned char *sha1,
        add_pending_object(rev, branch, name);
        add_pending_object(rev, &head->object, "^HEAD");
        head->object.flags |= UNINTERESTING;
-       prepare_revision_walk(rev);
+       if (prepare_revision_walk(rev))
+               die("revision walk setup failed");
        while ((commit = get_revision(rev)) != NULL) {
                char *oneline, *bol, *eol;