Merge branch 'rs/replay-wrong-onto-fix'

"git replay --onto=<commit> ...", when <commit> is mistyped,
started to segfault with recent change, which has been corrected.

* rs/replay-wrong-onto-fix:
  replay: move onto NULL check before first use

Author: gitster

builtin/replay.c

@@ -454,6 +454,9 @@ int cmd_replay(int argc,
 	determine_replay_mode(repo, &revs.cmdline, onto_name, &advance_name,
 			      &onto, &update_refs);
 
+	if (!onto) /* FIXME: Should handle replaying down to root commit */
+		die("Replaying down to root commit is not supported yet!");
+
 	/* Build reflog message */
 	if (advance_name_opt)
 		strbuf_addf(&reflog_msg, "replay --advance %s", advance_name_opt);
@@ -472,9 +475,6 @@ int cmd_replay(int argc,
 		}
 	}
 
-	if (!onto) /* FIXME: Should handle replaying down to root commit */
-		die("Replaying down to root commit is not supported yet!");
-
 	if (prepare_revision_walk(&revs) < 0) {
 		ret = error(_("error preparing revisions"));
 		goto cleanup;