# [PATCH] fast-export: ensure that a renamed file is printed after all references 4 messages from 2010-09-07 to 2010-09-08. Participants: Johannes Sixt, Elijah Newren. Thread: https://gitlist.dev/t/25026 ## Johannes Sixt, 2010-09-07 19:33 Subject: [PATCH] fast-export: ensure that a renamed file is printed after all references Message-ID: <201009072133.02930.j6t@kdbg.org> URL: https://gitlist.dev/e/201009072133.02930.j6t%40kdbg.org ``` t9350 sets up a commit where a file is both copied and renamed. The output of fast-export for this commit should look like this: author ... committer ... from :19 C "file2" "file4" R "file2" "file5" The order of the two modification lines is derived from the result that the diff machinery produces. 060df62 (fast-export: Fix output order of D/F changes) inserted a qsort call that modifies the order of the diff result. Unfortunately, qsort need not be stable. Therefore, it is possible that the 'R' line appears before the 'C' line and the resulting fast-import stream is incorrect. Fix it by forcing that the rename entry is printed after all other modification lines with the same file name. Signed-off-by: Johannes Sixt --- builtin/fast-export.c | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-) diff --git a/builtin/fast-export.c b/builtin/fast-export.c index 965e90e..007bba6 100644 --- a/builtin/fast-export.c +++ b/builtin/fast-export.c @@ -166,7 +166,15 @@ static int depth_first(const void *a_, const void *b_) cmp = memcmp(name_a, name_b, len); if (cmp) return cmp; - return (len_b - len_a); + cmp = len_b - len_a; + if (cmp) + return cmp; + /* + * Move 'R'ename entries last so that all references of the file + * appear in the output before it is renamed (e.g., when a file + * was copied and renamed in the same commit). + */ + return (a->status == 'R') - (b->status == 'R'); } static void show_filemodify(struct diff_queue_struct *q, -- 1.7.1.402.gf1eeb ``` ## Elijah Newren, 2010-09-08 05:46 Subject: Re: [PATCH] fast-export: ensure that a renamed file is printed after all references Message-ID: URL: https://gitlist.dev/e/AANLkTim4iuDOG9U1epcafWarckaa6ZnxCOpfJW8KJW_m%40mail.gmail.com In-Reply-To: <201009072133.02930.j6t@kdbg.org> ``` Hi, On Tue, Sep 7, 2010 at 1:33 PM, Johannes Sixt wrote: > t9350 sets up a commit where a file is both copied and renamed. The output > of fast-export for this commit should look like this: > >  author ... >  committer ... >  from :19 >  C "file2" "file4" >  R "file2" "file5" > > The order of the two modification lines is derived from the result that > the diff machinery produces. > > 060df62 (fast-export: Fix output order of D/F changes) inserted a qsort > call that modifies the order of the diff result. Unfortunately, qsort need > not be stable. Therefore, it is possible that the 'R' line appears before > the 'C' line and the resulting fast-import stream is incorrect. > > Fix it by forcing that the rename entry is printed after all other > modification lines with the same file name. Patch and description looks good to me...however, I was a little surprised to see no testsuite addition or additional explanation. Are you seeing some t9350 tests fail on some platform despite passing on linux? Elijah ``` ## Johannes Sixt, 2010-09-08 18:47 Subject: Re: [PATCH] fast-export: ensure that a renamed file is printed after all references Message-ID: <201009082047.50083.j6t@kdbg.org> URL: https://gitlist.dev/e/201009082047.50083.j6t%40kdbg.org In-Reply-To: ``` On Mittwoch, 8. September 2010, Elijah Newren wrote: > Patch and description looks good to me...however, I was a little > surprised to see no testsuite addition or additional explanation. Are > you seeing some t9350 tests fail on some platform despite passing on > linux? Yes, I see the problem in t9350 on Windows. It is impossible to write a test for it because the test would depend on the unspecified behavior of qsort. BTW, I don't know whether the diff machinery guarantees to produce 'C' and 'R' records in this order. If there is no such guarantee, then fast-export would have been broken even before 060df62. -- Hannes ``` ## Elijah Newren, 2010-09-08 19:26 Subject: Re: [PATCH] fast-export: ensure that a renamed file is printed after all references Message-ID: URL: https://gitlist.dev/e/AANLkTimS96c1YFC%2BUUw0iRoPVT%3DCOFhDRoSO1cNHYhTf%40mail.gmail.com In-Reply-To: <201009082047.50083.j6t@kdbg.org> ``` On Wed, Sep 8, 2010 at 12:47 PM, Johannes Sixt wrote: > On Mittwoch, 8. September 2010, Elijah Newren wrote: >> Patch and description looks good to me...however, I was a little >> surprised to see no testsuite addition or additional explanation.  Are >> you seeing some t9350 tests fail on some platform despite passing on >> linux? > > Yes, I see the problem in t9350 on Windows. It is impossible to write a test > for it because the test would depend on the unspecified behavior of qsort. Makes sense. Would it be worth briefly mentioning Windows in the commit message? Either way, Acked-by: Elijah Newren > BTW, I don't know whether the diff machinery guarantees to produce 'C' and 'R' > records in this order. If there is no such guarantee, then fast-export would > have been broken even before 060df62. ```