From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-3.7 required=3.0 tests=AWL,BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD shortcircuit=no autolearn=ham autolearn_force=no version=3.4.0 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id D0FE7208E3 for ; Tue, 5 Sep 2017 20:36:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753156AbdIEUg1 (ORCPT ); Tue, 5 Sep 2017 16:36:27 -0400 Received: from cloud.peff.net ([104.130.231.41]:57808 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1753168AbdIEUgZ (ORCPT ); Tue, 5 Sep 2017 16:36:25 -0400 Received: (qmail 1843 invoked by uid 109); 5 Sep 2017 20:36:25 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with SMTP; Tue, 05 Sep 2017 20:36:25 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 16633 invoked by uid 111); 5 Sep 2017 20:36:57 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) by peff.net (qpsmtpd/0.94) with SMTP; Tue, 05 Sep 2017 16:36:57 -0400 Authentication-Results: peff.net; auth=none Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Tue, 05 Sep 2017 16:36:23 -0400 Date: Tue, 5 Sep 2017 16:36:23 -0400 From: Jeff King To: Martin =?utf-8?B?w4VncmVu?= Cc: Junio C Hamano , Michael Haggerty , Git Mailing List Subject: Re: [PATCH v3 1/3] refs/files-backend: add longer-scoped copy of string to list Message-ID: <20170905203622.6fs3hr7zfa7mwpqn@sigill.intra.peff.net> References: <4b4c0d178ad2216eecbc49fb6f54dd8a1d1ac119.1504024261.git.martin.agren@gmail.com> <91e365b5-6a5d-1e1c-ab7a-579efa7c1ae8@alum.mit.edu> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Tue, Sep 05, 2017 at 07:24:18PM +0200, Martin Ågren wrote: > > And from that point of view, doesn't split_head_update() wants a > > similar fix? It attempts to insert "HEAD", makes sure it hasn't > > been inserted and then hangs a new update transaction as its util. > > It is not wrong per-se from purely leak-prevention point of view, > > as that "HEAD" is a literal string we woudn't even want to free, > > but from logical/"what each data means" point of view, it still > > feels wrong. > > There is a "Special hack" comment related to this, and I don't feel > particularly confident that I could make any meaningful contribution in > this area. To be honest, I don't immediately see in which direction your > suggestion/idea/thought is going, which tells me I should not be making > a mess out of it. :-) I noticed the HEAD funniness, too, when looking at this earlier. I agree with Junio that it's not quite consistent with the general rule of "string list items point to their refnames", but I don't think it matters in practice. I think the fix, if we wanted to do one, would be similar to what you did in split_symref_update(). Like: diff --git a/refs/files-backend.c b/refs/files-backend.c index f3455609d6..3f9deff902 100644 --- a/refs/files-backend.c +++ b/refs/files-backend.c @@ -2095,8 +2095,7 @@ static int split_head_update(struct ref_update *update, * transaction. This insertion is O(N) in the transaction * size, but it happens at most once per transaction. */ - item = string_list_insert(affected_refnames, "HEAD"); - if (item->util) { + if (string_list_has_string(affected_refnames, "HEAD")) { /* An entry already existed */ strbuf_addf(err, "multiple updates for 'HEAD' (including one " @@ -2111,6 +2110,7 @@ static int split_head_update(struct ref_update *update, update->new_oid.hash, update->old_oid.hash, update->msg); + item = string_list_insert(affected_refnames, new_update->refname); item->util = new_update; return 0; -Peff