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=-5.2 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 6000A203E1 for ; Wed, 27 Jul 2016 16:37:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756831AbcG0QhX (ORCPT ); Wed, 27 Jul 2016 12:37:23 -0400 Received: from bsmtp3.bon.at ([213.33.87.17]:8742 "EHLO bsmtp3.bon.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755485AbcG0QhW (ORCPT ); Wed, 27 Jul 2016 12:37:22 -0400 Received: from dx.site (unknown [93.83.142.38]) by bsmtp3.bon.at (Postfix) with ESMTPSA id 3s00yS1pWfz5tlJ; Wed, 27 Jul 2016 18:37:20 +0200 (CEST) Received: from [IPv6:::1] (localhost [IPv6:::1]) by dx.site (Postfix) with ESMTP id A958952C6; Wed, 27 Jul 2016 18:37:19 +0200 (CEST) Subject: Re: [PATCH] t4130: work around Windows limitation To: Johannes Schindelin References: <5bd59ca2f87e388350f3c8fb17c9a287661cd055.1469623136.git.johannes.schindelin@gmx.de> Cc: git@vger.kernel.org, Junio C Hamano From: Johannes Sixt Message-ID: <9d167448-84ce-e368-0bb4-41aa4452268d@kdbg.org> Date: Wed, 27 Jul 2016 18:37:19 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2 MIME-Version: 1.0 In-Reply-To: <5bd59ca2f87e388350f3c8fb17c9a287661cd055.1469623136.git.johannes.schindelin@gmx.de> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Am 27.07.2016 um 14:39 schrieb Johannes Schindelin: > On Windows, it is already pretty expensive to try to recreate the stat() > data that Git assumes is cheap to obtain. To make things halfway decent > in performance, we even have to skip emulating the inode and to > determine the number of hard links. > > This is not a huge problem, usually, as either the size or the mtime or > the ctime are tell-tale enough to say when a file has changed, and even > if not, those changes are typically made after the index file was > written, triggering a rehashing of the files' contents. > > The t4130-apply-criss-cross-rename test case, however, requires the > inode to determine that files of equal size were swapped, as renaming > files does not update their mtime. And even if we use > nanosecond-precision mtimes on Windows, the file system's time > granularity is typically much coarser (100ms for NTFS, 2s for FAT). > > That means that every once in a while, t4130 fails on Windows. > > This patch provides the work-around by pretending that the index file > was written earlier than it actually was. > > Signed-off-by: Johannes Schindelin > --- > Published-As: https://github.com/dscho/git/releases/tag/t4130-mingw-v1 > t/t4130-apply-criss-cross-rename.sh | 16 ++++++++++++++++ > 1 file changed, 16 insertions(+) > > diff --git a/t/t4130-apply-criss-cross-rename.sh b/t/t4130-apply-criss-cross-rename.sh > index d173acd..ee91af8 100755 > --- a/t/t4130-apply-criss-cross-rename.sh > +++ b/t/t4130-apply-criss-cross-rename.sh > @@ -29,6 +29,14 @@ test_expect_success 'criss-cross rename' ' > ' > > test_expect_success 'diff -M -B' ' > + if test_have_prereq MINGW > + then > + # On Windows it is prohbitively expensive to retrieve the > + # equivalent of an "inode" when calling stat(), therefore we > + # rely on mtime/ctime/size changes to let us know whether a > + # file has changed, including the mtime relative to the index. > + test-chmtime -1 .git/index > + fi && > git diff -M -B > diff && > git reset --hard > > @@ -52,6 +60,14 @@ test_expect_success 'criss-cross rename' ' > ' > > test_expect_success 'diff -M -B' ' > + if test_have_prereq MINGW > + then > + # On Windows it is prohbitively expensive to retrieve the > + # equivalent of an "inode" when calling stat(), therefore we > + # rely on mtime/ctime/size changes to let us know whether a > + # file has changed, including the mtime relative to the index. > + test-chmtime -1 .git/index > + fi && > git diff -M -B > diff && > git reset --hard > ' > How about this instead? It makes the sizes of the files different, which is a bit less obscure, IMHO. ---- 8< ---- [PATCH] t4130: work around Windows limitation On Windows, it is already pretty expensive to try to recreate the stat() data that Git assumes is cheap to obtain. To make things halfway decent in performance, we even have to skip emulating the inode and to determine the number of hard links. This is not a huge problem, usually, as either the size or the mtime or the ctime are tell-tale enough to say when a file has changed, and even if not, those changes are typically made after the index file was written, triggering a rehashing of the files' contents. The t4130-apply-criss-cross-rename test case, however, requires the inode to determine that files of equal size were swapped, as renaming files does not update their mtime. Every once in a while, t4130 fails on Windows of this missing piece. Equal file sizes are not crucial for the test cases, however. Hence, generate files with different sizes so that there is some property that the swapped files can be discovered reliably even on Windows. Helped-by: Johannes Schindelin Signed-off-by: Johannes Sixt --- t/t4130-apply-criss-cross-rename.sh | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/t/t4130-apply-criss-cross-rename.sh b/t/t4130-apply-criss-cross-rename.sh index d173acd..f8a313b 100755 --- a/t/t4130-apply-criss-cross-rename.sh +++ b/t/t4130-apply-criss-cross-rename.sh @@ -13,9 +13,13 @@ create_file() { } test_expect_success 'setup' ' - create_file file1 "File1 contents" && - create_file file2 "File2 contents" && - create_file file3 "File3 contents" && + # Ensure that file sizes are different, because on Windows + # lstat() does not discover inode numbers, and we need + # other properties to discover swapped files + # (mtime is not always different, either). + create_file file1 "some content" && + create_file file2 "some other content" && + create_file file3 "again something else" && git add file1 file2 file3 && git commit -m 1 ' -- 2.9.0.443.ga8520ad