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=-3.9 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 7DF1B207E4 for ; Sat, 29 Apr 2017 00:28:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1423987AbdD2A2R (ORCPT ); Fri, 28 Apr 2017 20:28:17 -0400 Received: from mail-pf0-f175.google.com ([209.85.192.175]:33700 "EHLO mail-pf0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1164617AbdD2A2P (ORCPT ); Fri, 28 Apr 2017 20:28:15 -0400 Received: by mail-pf0-f175.google.com with SMTP id q20so1460282pfg.0 for ; Fri, 28 Apr 2017 17:28:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc; bh=Ls7T8/4IFgmrEAJ3HQnJSJO28x7csMka3+dNWt4++KE=; b=JSK/WLEW8DjlcYW6sFJthRlphc96Mv+cdqsnOLXmK8uBmW0u01mZ42xrfn2zTjLXMp n8888TNe31+qn0emUsKBIUa0cuCnxnPN2C4s0mcTJAhC+GXRGPu74z9XWBeI/txiWTLn SVAgF9XRoJdcVYgDNOXFQljtoOXZTHbobUSwQWxqnR6kpqkwLzQfOCgAyK/HKWLANrLR y1Ak/dxy1jTaZSF4aIOMhzHvBukrtVYudVV7BmQ2JXiw34VeL//6vrokZHEmEk07FBMN bhbJynYNfy8jGqfPW1lAR1zXc6RuoU2yByU39mGK8lgmtYtpgevzW7uDOcaVZSspOKpw hmag== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc; bh=Ls7T8/4IFgmrEAJ3HQnJSJO28x7csMka3+dNWt4++KE=; b=Atb2LXNPejx3Sq2gkB6HydfMULt/D3G8vbIZHJfU9J97evAg83bG5jQv09zRwAAiq8 6dHmwvKE91g6oJjSifWgF3wU/y1blNaA57GTprJy39VjbQslsm8Cb/l+FexUFvepIZNM yN6T8K3yZHVs5tFu3UW3blTSbhYW1dUQZtzzFCFPoDvmoehfl514F2I+t2V3aCYuBFiW xq5YqSJWAX3UxKEyLnScjic3d2NiAeXnporFvPg+OHaJ4Javk+yI9G/0NKz9WC8VqaII yZk5+nzcc4mapLFl8Dumg2GfphQAc1ppW4hSB3qFVTp2K0eEeiMllxALr6yfXTsrezi4 GQOg== X-Gm-Message-State: AN3rC/5I/fRLe6ygSPTyeqUGl3TXjXgOV+gr4S0scfW1wUXD6hyVD+FE FoOdpN8Pd3r3t6JYGCVOF0AQIw6efoq2 X-Received: by 10.98.72.88 with SMTP id v85mr15091911pfa.8.1493425694632; Fri, 28 Apr 2017 17:28:14 -0700 (PDT) MIME-Version: 1.0 Received: by 10.100.153.156 with HTTP; Fri, 28 Apr 2017 17:28:14 -0700 (PDT) In-Reply-To: <20170428235402.162251-6-bmwill@google.com> References: <20170428235402.162251-1-bmwill@google.com> <20170428235402.162251-6-bmwill@google.com> From: Stefan Beller Date: Fri, 28 Apr 2017 17:28:14 -0700 Message-ID: Subject: Re: [PATCH 5/6] submodule: improve submodule_has_commits To: Brandon Williams Cc: "git@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org On Fri, Apr 28, 2017 at 4:54 PM, Brandon Williams wrote: > Teach 'submodule_has_commits()' to ensure that if a commit exists in a > submodule, that it is also reachable from a ref. > > This is a prepritory step prior to merging the logic which checkes for s/prepritory/preparatory/ s/checkes/checks/ This is the first commit in the series that changes user observable behavior, I guess there will be tests in a later patch? Can you elaborate in this commit message more about why it is useful (or at least harmless for performing this check in the case of fetch/push)? > diff --git a/submodule.c b/submodule.c > index 3bcf44521..100d31d39 100644 > --- a/submodule.c > +++ b/submodule.c > @@ -648,6 +648,30 @@ static int submodule_has_commits(const char *path, struct oid_array *commits) > return 0; > > oid_array_for_each_unique(commits, check_has_commit, &has_commit); > + > + if (has_commit) { > + /* > + * Even if the submodule is checked out and the commit is > + * present, make sure it is reachable from a ref. > + */ > + struct child_process cp = CHILD_PROCESS_INIT; > + struct strbuf out = STRBUF_INIT; > + > + argv_array_pushl(&cp.args, "rev-list", "-n", "1", NULL); > + oid_array_for_each_unique(commits, append_oid_to_argv, &cp.args); > + argv_array_pushl(&cp.args, "--not", "--all", NULL); > + > + prepare_submodule_repo_env(&cp.env_array); > + cp.git_cmd = 1; > + cp.no_stdin = 1; > + cp.dir = path; > + > + if (capture_command(&cp, &out, 1024) || out.len) > + has_commit = 0; So if we fail to launch capture_command, we assume we do not have the commits? capture_command can fail for reasons that are hard to track down or even spurious (OOM due to excessive output, disk failure, corrupt repo, error in executing the process, getting a signal and so on), some of them are ok to ignore, others should never be ignored. So I'd rather die on capture_command, and inspect out.len only in case of successful capturing. In addition to that we're only interested if there is any output, such that we can optimize further: c.f. http://public-inbox.org/git/20170324223848.GH31294@aiede.mtv.corp.google.com/ if (start_command(&cp)) die("cannot start git-rev-list in submodule'%s', sub->path); /* read only one character, if any */ if (xread(cp.out, &tmp, 1); has_commit = 0; /* * close cp.out, such that the child may get SIGPIPE, upon which * it dies (silently, maybe we need to suppress cp.err ?) */ close(cp.out); /* * Though we need to be nitpicky about finish_command IIUC by now: * TODO(sbeller): if this turns out to be true, fixup is_submodule_modified */ int code = finish_command(&cp); if (!code && code != 128 + SIGPIPE) die("git rev-list failed in submodule'%s'", sub->path); Upon rereading the patch, I notice the '-n 1', which would make the optimized code above useless, so just consider it food for thought. Thanks, Stefan