Re: [PATCH v2] Teach git apply to respect core.fileMode settings

["Torsten Bögershausen" <tboegi@web.de>]

On Tue, Dec 19, 2023 at 06:30:45PM +0000, Chandra Pratap via GitGitGadget wrote:
> From: Chandra Pratap <chandrapratap3519@gmail.com>
>

Thanks for working on this, some small nit-picks inline.

> When applying a patch that adds an executable file, git apply
> ignores the core.fileMode setting (core.fileMode in git config
> specifies whether the executable bit on files in the working tree
> should be honored or not) resulting in warnings like:
>
> warning: script.sh has type 100644, expected 100755
>
> even when core.fileMode is set to false, which is undesired. This
> is extra true for systems like Windows, which don't rely on "lsat()".

Small typo here: lsat() should be lstat(). But being nit-picking (and simplifying):
Windows does not provide an implementation, so Git for Windows does it's own,
which currently does not implement the x-bit(s).
In short: The ', which don't rely on "lsat()' could probably just removed.

>
> Fix this by inferring the correct file mode from the existing
> index entry when core.filemode is set to false. The added
> test case helps verify the change and prevents future regression.

Another nit-pick, sorry for that, I try to convince everybody to not
use "added".
So may be
Add a test case that verifies the change and prevents future regression.

>
> Reviewed-by: Johannes Schindelin <johannes.schindelin@gmail.com>
> Signed-off-by: Chandra Pratap <chandrapratap3519@gmail.com>
> ---
>     apply: make git apply respect core.fileMode settings
>
>     Closes issue #1555 on GitHub.
>

[]
>
>
>  apply.c                   |  8 ++++++--
>  t/t4129-apply-samemode.sh | 25 +++++++++++++++++++++++++
>  2 files changed, 31 insertions(+), 2 deletions(-)
>
> diff --git a/apply.c b/apply.c
> index 3d69fec836d..58f26c40413 100644
> --- a/apply.c
> +++ b/apply.c
> @@ -3778,8 +3778,12 @@ static int check_preimage(struct apply_state *state,
>  		return error_errno("%s", old_name);
>  	}
>
> -	if (!state->cached && !previous)
> -		st_mode = ce_mode_from_stat(*ce, st->st_mode);

> +	if (!state->cached && !previous) {
> +		if (!trust_executable_bit)
> +			st_mode = *ce ? (*ce)->ce_mode : patch->old_mode;
> +		else
> +			st_mode = ce_mode_from_stat(*ce, st->st_mode);
> +	}
>
>  	if (patch->is_new < 0)
>  		patch->is_new = 0;
> diff --git a/t/t4129-apply-samemode.sh b/t/t4129-apply-samemode.sh
> index e7a7295f1b6..73fc472b246 100755
> --- a/t/t4129-apply-samemode.sh
> +++ b/t/t4129-apply-samemode.sh
> @@ -101,4 +101,29 @@ test_expect_success POSIXPERM 'do not use core.sharedRepository for working tree
>  	)
>  '
>
> +test_expect_success 'ensure git apply respects core.fileMode' '

Small nit-pick:
The "ensure" is probably not needed, all tests ensure something.

> +	test_config core.fileMode false &&
> +	echo true >script.sh &&
> +	git add --chmod=+x script.sh &&
> +	git ls-files -s script.sh | grep "^100755" &&
> +	test_tick && git commit -m "Add script" &&
> +	git ls-tree -r HEAD script.sh | grep "^100755" &&
> +
> +	echo true >>script.sh &&
> +	test_tick && git commit -m "Modify script" script.sh &&
> +	git format-patch -1 --stdout >patch &&
> +	grep "index.*100755" patch &&
> +
> +	git switch -c branch HEAD^ &&
> +	git apply --index patch 2>err &&
> +	! grep "has type 100644, expected 100755" err &&

This feels somewhat volatile against future changes.
grep-ing for things that are not there, without verifying
that they are there, without this patch.

On my test system, there is no message at all, so a

test_must_be_empty err &&

feels more "stable".

> +	git restore -S script.sh && git restore script.sh &&
> +
> +	git apply patch 2>err &&
> +	! grep "has type 100644, expected 100755" err &&
> +
> +	git apply --cached patch 2>err &&
> +	! grep "has type 100644, expected 100755" err
> +'
> +
>  test_done