From patchwork Wed May 22 04:31:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jeff King X-Patchwork-Id: 10954785 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 65A67112C for ; Wed, 22 May 2019 04:31:51 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 463CE28A31 for ; Wed, 22 May 2019 04:31:51 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3685E28AAF; Wed, 22 May 2019 04:31:51 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A9C5828A31 for ; Wed, 22 May 2019 04:31:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725850AbfEVEbt (ORCPT ); Wed, 22 May 2019 00:31:49 -0400 Received: from cloud.peff.net ([104.130.231.41]:35722 "HELO cloud.peff.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1725801AbfEVEbt (ORCPT ); Wed, 22 May 2019 00:31:49 -0400 Received: (qmail 14612 invoked by uid 109); 22 May 2019 04:31:49 -0000 Received: from Unknown (HELO peff.net) (10.0.1.2) by cloud.peff.net (qpsmtpd/0.94) with SMTP; Wed, 22 May 2019 04:31:49 +0000 Authentication-Results: cloud.peff.net; auth=none Received: (qmail 19493 invoked by uid 111); 22 May 2019 04:32:29 -0000 Received: from sigill.intra.peff.net (HELO sigill.intra.peff.net) (10.0.0.7) by peff.net (qpsmtpd/0.94) with (ECDHE-RSA-AES256-GCM-SHA384 encrypted) SMTP; Wed, 22 May 2019 00:32:29 -0400 Authentication-Results: peff.net; auth=none Received: by sigill.intra.peff.net (sSMTP sendmail emulation); Wed, 22 May 2019 00:31:46 -0400 Date: Wed, 22 May 2019 00:31:46 -0400 From: Jeff King To: Bryan Turner Cc: Git Users Subject: [PATCH] upload-pack: strip namespace from symref data Message-ID: <20190522043146.GA2563@sigill.intra.peff.net> References: <20190521214630.GD14807@sigill.intra.peff.net> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190521214630.GD14807@sigill.intra.peff.net> Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Since 7171d8c15f (upload-pack: send symbolic ref information as capability, 2013-09-17), we've sent cloning and fetching clients special information about which branch HEAD is pointing to, so that they don't have to guess based on matching up commit ids. However, this feature has never worked properly with the GIT_NAMESPACE feature. Because upload-pack uses head_ref_namespaced(find_symref), we do find and report on refs/namespaces/foo/HEAD instead of the actual HEAD of the repo. This makes sense, since the branch pointed to by the top-level HEAD may not be advertised at all. But we do two things wrong: 1. We report the full name refs/namespaces/foo/HEAD, instead of just HEAD. Meaning no client is going to bother doing anything with that symref, since we're not otherwise advertising it. 2. We report the symref destination using its full name (e.g., refs/namespaces/foo/refs/heads/master). That's similarly useless to the client, who only saw "refs/heads/master" in the advertisement. We should be stripping the namespace prefix off of both places (which this patch fixes). Likely nobody noticed because bug (1) means that from the client's perspective, we did not report on HEAD at all. And thus it uses the pre-7171d8c15f fallback code to guess the correct HEAD, which is usually right. It only falls down in ambiguous cases (like the one laid out in the included test). This also means that we don't have to worry about breaking anybody who was putting pre-stripped names into their namespace symrefs when we fix bug (2). Because of bug (1), nobody would have been using the symref we advertised in the first place (not to mention that those symrefs would have appeared broken for any non-namespaced access). Note that we have separate fixes here for the v0 and v2 protocols. The symref advertisement moved in v2 to be a part of the ls-refs command. This actually gets part (1) right, since the symref annotation piggy-backs on the existing ref advertisement, which is properly stripped. But it still needs a fix for part (2). The included tests cover both protocols. Reported-by: Bryan Turner Signed-off-by: Jeff King --- This is the same as my earlier fix, but with the v2 bit added, and of course tests and a commit message. Thanks (as usual) for a helpful bug report. I don't know if we have a general philosophy for testing v0 versus v2. Without specifying the protocol at all, we'd catch the former on a regular run and the latter under a GIT_TEST_PROTOCOL_VERSION=2 run. So we _could_ just rely on that, but since I had to do two separate fixes, it made sense to me to include explicit tests. ls-refs.c | 3 ++- t/t5509-fetch-push-namespaces.sh | 28 ++++++++++++++++++++++++++++ upload-pack.c | 4 ++-- 3 files changed, 32 insertions(+), 3 deletions(-) diff --git a/ls-refs.c b/ls-refs.c index 0a7dbc6442..818aef70a0 100644 --- a/ls-refs.c +++ b/ls-refs.c @@ -57,7 +57,8 @@ static int send_ref(const char *refname, const struct object_id *oid, if (!symref_target) die("'%s' is a symref but it is not?", refname); - strbuf_addf(&refline, " symref-target:%s", symref_target); + strbuf_addf(&refline, " symref-target:%s", + strip_namespace(symref_target)); } if (data->peel) { diff --git a/t/t5509-fetch-push-namespaces.sh b/t/t5509-fetch-push-namespaces.sh index c88df78c0b..75cbfcc392 100755 --- a/t/t5509-fetch-push-namespaces.sh +++ b/t/t5509-fetch-push-namespaces.sh @@ -124,4 +124,32 @@ test_expect_success 'try to update a hidden full ref' ' test_must_fail git -C original push pushee-namespaced master ' +test_expect_success 'set up ambiguous HEAD' ' + git init ambiguous && + ( + cd ambiguous && + git commit --allow-empty -m foo && + git update-ref refs/namespaces/ns/refs/heads/one HEAD && + git update-ref refs/namespaces/ns/refs/heads/two HEAD && + git symbolic-ref refs/namespaces/ns/HEAD \ + refs/namespaces/ns/refs/heads/two + ) +' + +test_expect_success 'clone chooses correct HEAD (v0)' ' + GIT_NAMESPACE=ns git -c protocol.version=0 \ + clone ambiguous ambiguous-v0 && + echo refs/heads/two >expect && + git -C ambiguous-v0 symbolic-ref HEAD >actual && + test_cmp expect actual +' + +test_expect_success 'clone chooses correct HEAD (v2)' ' + GIT_NAMESPACE=ns git -c protocol.version=2 \ + clone ambiguous ambiguous-v2 && + echo refs/heads/two >expect && + git -C ambiguous-v2 symbolic-ref HEAD >actual && + test_cmp expect actual +' + test_done diff --git a/upload-pack.c b/upload-pack.c index 24298913c0..4d2129e7fc 100644 --- a/upload-pack.c +++ b/upload-pack.c @@ -1037,8 +1037,8 @@ static int find_symref(const char *refname, const struct object_id *oid, symref_target = resolve_ref_unsafe(refname, 0, NULL, &flag); if (!symref_target || (flag & REF_ISSYMREF) == 0) die("'%s' is a symref but it is not?", refname); - item = string_list_append(cb_data, refname); - item->util = xstrdup(symref_target); + item = string_list_append(cb_data, strip_namespace(refname)); + item->util = xstrdup(strip_namespace(symref_target)); return 0; }