builtin-push: don't access freed transport->url

Move the failed push message to before transport_disconnect() so that
it doesn't access transport->url after transport has been free()'d (in
transport_disconnect()).

Additionally, make the failed push message more accurate by moving it
before transport_disconnect(), so that it doesn't report errors due
to a failed disconnect.
Signed-off-by: NTay Ray Chuan <rctay89@gmail.com>
Acked-by: NDaniel Barkalow <barkalow@iabervon.org>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

builtin-push.c

@@ -102,13 +102,14 @@ static int push_with_options(struct transport *transport, int flags)
 		fprintf(stderr, "Pushing to %s\n", transport->url);
 	err = transport_push(transport, refspec_nr, refspec, flags,
 			     &nonfastforward);
+	if (err != 0)
+		error("failed to push some refs to '%s'", transport->url);
+
 	err |= transport_disconnect(transport);
 
 	if (!err)
 		return 0;
 
-	error("failed to push some refs to '%s'", transport->url);
-
 	if (nonfastforward && advice_push_nonfastforward) {
 		printf("To prevent you from losing history, non-fast-forward updates were rejected\n"
 		       "Merge the remote changes before pushing again.  See the 'non-fast-forward'\n"