Re: [PATCH] t9001-send-email.sh: fix expected absolute paths on Windows

> On Mon, May 24 2021, Johannes Sixt wrote:
>
> Also CC-ing Robert Foss <robert.foss@linaro.org>, I last touched this
> code, but the fallout is ultimately from his c8243933c74
> (git-send-email: Respect core.hooksPath setting, 2021-03-23).
>
>> Git for Windows is a native Windows program that works with native
>> absolute paths in the drive letter style C:\dir. The auxiliary
>> infrastructure is based on MSYS2, which uses POSIX style /C/dir.
>>
>> When we test for output of absolute paths produced by git.exe, we
>> usally have to expect C:\dir style paths. To produce such expected
>> paths, we have to use $(pwd) in the test scripts; the alternative,
>> $PWD, produces a POSIX style path. ($PWD is a shell variable, and the
>> shell is bash, an MSYS2 program, and operates in the POSIX realm.)
>>
>> There are two recently added tests that were written to expect C:\dir
>> paths. The output that is tested is produced by `git send-email`, but
>> behind the scenes, this is a Perl script, which also works in the
>> POSIX realm and produces /C/dir style output.
>>
>> In the first test case that is changed here, replace $(pwd) by $PWD
>> so that the expected path is constructed using /C/dir style.
>>
>> The second test case sets core.hooksPath to an absolute path. Since
>> the test script talks to native git.exe, it is supposed to place a
>> C:/dir style path into the configuration; therefore, keep $(pwd).
>> When this configuration value is consumed by the Perl script, it is
>> transformed to /C/dir style by the MSYS2 layer and echoed back in
>> this form in the error message. Hence, do use $PWD for the expected
>> value.
>>
>> Signed-off-by: Johannes Sixt <j6t@kdbg.org>
>> ---
>>  When I say "the configuration is transformed to /C/dir style", I am
>>  actually hand-waving: I can observe that a transformation must
>>  happen somewhere, but I actually do not know where the conversion
>>  really happens. "The MSYS2 layer" is my best qualified guess.
>>
>>  t/t9001-send-email.sh | 7 +++----
>>  1 file changed, 3 insertions(+), 4 deletions(-)
>>
>> diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
>> index 65b3035371..68bebc505b 100755
>> --- a/t/t9001-send-email.sh
>> +++ b/t/t9001-send-email.sh
>> @@ -539,15 +539,14 @@ test_expect_success $PREREQ "--validate respects relative core.hooksPath path" '
>>  	test_path_is_file my-hooks.ran &&
>>  	cat >expect <<-EOF &&
>>  	fatal: longline.patch: rejected by sendemail-validate hook
>> -	fatal: command '"'"'$(pwd)/my-hooks/sendemail-validate'"'"' died with exit code 1
>> +	fatal: command '"'"'$PWD/my-hooks/sendemail-validate'"'"' died with exit code 1
>>  	warning: no patches were sent
>>  	EOF
>>  	test_cmp expect actual
>>  '
>>  
>>  test_expect_success $PREREQ "--validate respects absolute core.hooksPath path" '
>> -	hooks_path="$(pwd)/my-hooks" &&
>> -	test_config core.hooksPath "$hooks_path" &&
>> +	test_config core.hooksPath "$(pwd)/my-hooks" &&
>>  	test_when_finished "rm my-hooks.ran" &&
>>  	test_must_fail git send-email \
>>  		--from="Example <nobody@example.com>" \
>> @@ -558,7 +557,7 @@ test_expect_success $PREREQ "--validate respects absolute core.hooksPath path" '
>>  	test_path_is_file my-hooks.ran &&
>>  	cat >expect <<-EOF &&
>>  	fatal: longline.patch: rejected by sendemail-validate hook
>> -	fatal: command '"'"'$hooks_path/sendemail-validate'"'"' died with exit code 1
>> +	fatal: command '"'"'$PWD/my-hooks/sendemail-validate'"'"' died with exit code 1
>>  	warning: no patches were sent
>>  	EOF
>>  	test_cmp expect actual
>
> Does this alternate patch[1] also fix the issue? I don't have a Windows
> system on which to test this, but it seems to me like it should.

> I.e. the issue seems to me to me that we have an absolute path from
> --git-path, and one of Cwd.pm's or File::Spec.pm's ideas of what that
> absolute path should look like differs from ours.
>
> We have a sprinkle of File::Spec->file_name_is_absolute($dir) in Git.pm
> for some other stuff to deal with the same scenario, but I don't see why
> we need the abs_path() here at all.
>
> Either we have a relative path from "rev-parse --git-dir hooks", or an
> absolute one, in either case we feed it to Perl's
> system("some-relative-or-absolute-path").
>
> I have a parallel series where I did some send-email changes by just
> extracting the relevant code from Git.pm, since there were objections to
> changing the "public API". But in this case there's been no release with
> this, so presumably it's fine to just change it.
>
> 1.
>
> diff --git a/perl/Git.pm b/perl/Git.pm
> index 73ebbf80cc6..df6280ebab5 100644
> --- a/perl/Git.pm
> +++ b/perl/Git.pm
> @@ -629,8 +629,7 @@ sub hooks_path {
>  	my ($self) = @_;
>  
>  	my $dir = $self->command_oneline('rev-parse', '--git-path', 'hooks');
> -	my $abs = abs_path($dir);
> -	return $abs;
> +	return $dir;
>  }
>  
>  =item wc_path ()
> diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
> index 65b30353719..9c518462c3e 100755
> --- a/t/t9001-send-email.sh
> +++ b/t/t9001-send-email.sh
> @@ -539,7 +539,7 @@ test_expect_success $PREREQ "--validate respects relative core.hooksPath path" '
>  	test_path_is_file my-hooks.ran &&
>  	cat >expect <<-EOF &&
>  	fatal: longline.patch: rejected by sendemail-validate hook
> -	fatal: command '"'"'$(pwd)/my-hooks/sendemail-validate'"'"' died with exit code 1
> +	fatal: command '"'"'my-hooks/sendemail-validate'"'"' died with exit code 1
>  	warning: no patches were sent
>  	EOF
>  	test_cmp expect actual