From: Johannes Schindelin <Johannes.Schindelin@gmx.de>
To: Jeff King <peff@peff.net>
Cc: git@vger.kernel.org
Subject: Re: [PATCH] t7800: don't rely on reuse_worktree_file()
Date: Thu, 16 Jan 2020 22:08:22 +0100 (CET) [thread overview]
Message-ID: <nycvar.QRO.7.76.6.2001162207220.46@tvgsbejvaqbjf.bet> (raw)
In-Reply-To: <20200116181940.GA2945961@coredump.intra.peff.net>
Hi Peff,
On Thu, 16 Jan 2020, Jeff King wrote:
> A test in t7800 tries to make sure that when git-difftool runs an
> external tool that fails, it stops looking at files. Our fake failing
> tool prints the file name it was asked to diff before exiting non-zero,
> and then we confirm the output contains only that file.
>
> However, this subtly relies on our internal reuse_worktree_file().
> Because we're diffing between branches, the command run by difftool
> might see:
>
> - the git-stored filename (e.g., "file"), if we decided that the
> working tree contents were up-to-date with the object in the index
> and HEAD, and we could reuse them
>
> - a temporary filename (e.g. "/tmp/abc123_file") if we had to dump the
> contents from the object database
>
> If the latter case happens, then the test fails, because it's expecting
> the string "file". I discovered this when debugging something unrelated
> with reuse_worktree_file(). I _thought_ it should be able to be
> triggered by a racy-git situation, but running:
>
> ./t7800-difftool.sh --stress --run=2,13
>
> never seems to fail. However, by my reading of reuse_worktree_file(),
> this would probably always fail under Cygwin, because it sets
> NO_FAST_WORKING_DIRECTORY. At any rate, since reuse_worktree_file()
> is meant to be an optimization that may or may not trigger, our test
> should be robust either way.
>
> Instead of checking the filename, let's just make sure we got a single
> line of output (which would not be true if we continued after the first
> failure).
>
> Signed-off-by: Jeff King <peff@peff.net>
> ---
The reasoning and the patch seem sound to me.
Thanks,
Dscho
> t/t7800-difftool.sh | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/t/t7800-difftool.sh b/t/t7800-difftool.sh
> index 6bac9ed180..29b92907e2 100755
> --- a/t/t7800-difftool.sh
> +++ b/t/t7800-difftool.sh
> @@ -125,15 +125,14 @@ test_expect_success 'difftool stops on error with --trust-exit-code' '
> test_when_finished "rm -f for-diff .git/fail-right-file" &&
> test_when_finished "git reset -- for-diff" &&
> write_script .git/fail-right-file <<-\EOF &&
> - echo "$2"
> + echo failed
> exit 1
> EOF
> >for-diff &&
> git add for-diff &&
> - echo file >expect &&
> test_must_fail git difftool -y --trust-exit-code \
> --extcmd .git/fail-right-file branch >actual &&
> - test_cmp expect actual
> + test_line_count = 1 actual
> '
>
> test_expect_success 'difftool honors exit status if command not found' '
> --
> 2.25.0.318.gee4019ba55
>
next prev parent reply other threads:[~2020-01-16 21:08 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-16 18:19 [PATCH] t7800: don't rely on reuse_worktree_file() Jeff King
2020-01-16 21:08 ` Johannes Schindelin [this message]
2020-01-16 22:48 ` Junio C Hamano
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=nycvar.QRO.7.76.6.2001162207220.46@tvgsbejvaqbjf.bet \
--to=johannes.schindelin@gmx.de \
--cc=git@vger.kernel.org \
--cc=peff@peff.net \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).