Re: [PATCH 0/4] deterministic commit timestamps in tests

[Junio C Hamano <gitster@pobox.com>]

Junio C Hamano <gitster@pobox.com> writes:

> Heh, it already is in 'next' and I do not think it is worth
> rewinding and rebuilding to cause downstream folks an additional
> trouble.  I however think this updated solution is nicer and do not
> mind building on top i.e. "while an earlier change did unbreak the
> svn tests, relying on the current timestamps is not nice and here is
> an update".
>
> Having said that, I think it is more urgent to address the "ouch, we
> made it clera that repos with extensions.worktreeconfig set without
> marking them as repoformat v1 are broken and without giving users
> enough hints to recover" issue discussed elsewhere before -rc1 (and
> for that reason I do not think I can tag -rc1 today), so I'd
> backburner it.  This topic won't merge down from 'next' until final
> anyway.

Before I forget, here is what could be applied on top of the "fix
the starting timestamp for the world" step as a "further polishing
on top of the completed series".

-- >8 --
From: Jeff King <peff@peff.net>
Date: Wed, 15 Jul 2020 03:42:50 -0400
Subject: [PATCH] t9100: stop depending on commit timestamps

An earlier "fix" to this script gave up updating it not to rely on
the current time because we cannot control what timestamp subversion
gives its commits.  We however could solve the issue in a different
way and still use deterministic timestamps on Git commits.

One fix would be to sort the list of trees before removing duplicates,
but that loses information:

  - we do care that the fetched history is in the same order

  - there's a tree which appears twice in the history, and we'd want to
    make sure that it's there both times

So instead, let's de-duplicate using a hash (preserving the order), and
drop only lines with identical trees and subjects (preserving the tree
which appears twice, since it has different subjects each time).

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 t/t9100-git-svn-basic.sh | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/t/t9100-git-svn-basic.sh b/t/t9100-git-svn-basic.sh
index a89d338aa7..8dd9645ce5 100755
--- a/t/t9100-git-svn-basic.sh
+++ b/t/t9100-git-svn-basic.sh
@@ -8,10 +8,6 @@ GIT_SVN_LC_ALL=${LC_ALL:-$LANG}
 
 . ./lib-git-svn.sh
 
-# Make sure timestamps of commits created by Git interleave
-# with those created by "svn set-tree".
-unset GIT_COMMITTER_DATE
-
 case "$GIT_SVN_LC_ALL" in
 *.UTF-8)
 	test_set_prereq UTF8
@@ -204,8 +200,9 @@ GIT_SVN_ID=alt
 export GIT_SVN_ID
 test_expect_success "$name" \
     'git svn init "$svnrepo" && git svn fetch &&
-     git rev-list --pretty=raw remotes/git-svn | grep ^tree | uniq > a &&
-     git rev-list --pretty=raw remotes/alt | grep ^tree | uniq > b &&
+     git log --format="tree %T %s" remotes/git-svn |
+	awk "!seen[\$0]++ { print \$1, \$2 }" >a &&
+     git log --format="tree %T" alt >b &&
      test_cmp a b'
 
 name='check imported tree checksums expected tree checksums'
-- 
2.28.0-rc0