threads / bug / 62175

Bug report: Undocumented interaction of --exit-code and --ignore-space-change for file move

Subject: Bug report: Undocumented interaction of --exit-code and --ignore-space-change for file move

## tl;dr

3 messages between Sep 23, 2024 and Sep 23, 2024.

replies: 2people: 3as markdown or json

Ian Turner· Sep 23, 2024, 16:29 UTC · lore

Hi all,

I noticed that there an undocumented interaction of the --exit-code and --ignore-space-change flags to git diff, when the diff only contains file moves. Specifically, --ignore-space-change will cause git diff to return a zero exit code in this situation.

I am not sure if the problem is with the command behavior, or with the documentation.

STEPS TO REPRODUCE:

git init echo foo > a.txt git add a.txt git commit -m "A" git mv a.txt b.txt git commit -m "B" git diff --exit-code HEAD~1..HEAD # returns exit code 1 git diff --exit-code --ignore-space-change HEAD~1..HEAD # returns exit status 0

EXPECTED BEHAVIOR:

Both of the last two commands above should return nonzero exit status.

WORKAROUND:

As one might expect --no-renames undoes this behavior, although it also changes the diff output if not using --quiet:

git diff --exit-code --ignore-space-change --no-renames HEAD~1..HEAD # returns exit status 1

OTHER INFO:

Tested this on git 2.39.2 and git 2.41.0, both on Linux.

Regards,

Ian Turner

René Scharfe· Sep 23, 2024, 18:08 UTC · re: Ian Turner · lore

Re: Bug report: Undocumented interaction of --exit-code and --ignore-space-change for file move

Am 23.09.24 um 18:29 schrieb Ian Turner:

Show 33 quoted lines

> I noticed that there an undocumented interaction of the --exit-code
> and --ignore-space-change flags to git diff, when the diff only
> contains file moves. Specifically, --ignore-space-change will cause
> git diff to return a zero exit code in this situation.
>
> I am not sure if the problem is with the command behavior, or with
> the documentation.
>
> STEPS TO REPRODUCE:
>
> git init
> echo foo > a.txt
> git add a.txt
> git commit -m "A"
> git mv a.txt b.txt
> git commit -m "B"
> git diff --exit-code HEAD~1..HEAD # returns exit code 1
> git diff --exit-code --ignore-space-change HEAD~1..HEAD # returns exit status 0
>
> EXPECTED BEHAVIOR:
>
> Both of the last two commands above should return nonzero exit status.
>
> WORKAROUND:
>
> As one might expect --no-renames undoes this behavior, although it
> also changes the diff output if not using --quiet:
>
> git diff --exit-code --ignore-space-change --no-renames HEAD~1..HEAD # returns exit status 1
>
> OTHER INFO:
>
> Tested this on git 2.39.2 and git 2.41.0, both on Linux.

Thank you for the report!  It's a known bug in the code.

d7b97b7185 (diff: let external diffs report that changes are uninteresting, 2024-06-09) exposed it more widely, unfortunately, causing v2.46.0 and up to report the wrong exit code even without --ignore-space-change.

87cf96094a (diff: report copies and renames as changes in run_diff_cmd(), 2024-09-08) fixes it, but it's not in any release, yet.

René

Junio C Hamano· Sep 23, 2024, 22:32 UTC · re: René Scharfe · lore

Re: Bug report: Undocumented interaction of --exit-code and --ignore-space-change for file move

René Scharfe <l.s.r@web.de> writes:

> 87cf96094a (diff: report copies and renames as changes in
> run_diff_cmd(), 2024-09-08) fixes it, but it's not in any release, yet.

Thanks.

It should first appear in Git 2.46.2 and would be in Git 2.47.