Subject: Re: [PATCH 2/2] send-email: don't needlessly abs_path() the core.hooksPath

From: Ævar Arnfjörð Bjarmason <[email-masked]>
Date: Tue, 25 May 2021 08:13:52 +0200

On Tue, May 25 2021, Ævar Arnfjörð Bjarmason wrote:

> On Tue, May 25 2021, Junio C Hamano wrote:
>
>> Ævar Arnfjörð Bjarmason  <[email-masked]> writes:
>>
>>> In c8243933c74 (git-send-email: Respect core.hooksPath setting,
>>> 2021-03-23) we started supporting core.hooksPath in "send-email". It's
>>> been reported that on Windows[1] doing this by calling abs_path()
>>> results in different canonicalizations of the absolute path.
>>
>> I see the author of that patch CC'ed; the change in question
>> explains why we switched from "the hooks directory immediately under
>> $repo->repo_path()" to "ask 'rev-parse --git-path hooks'", but it
>> does not say why we call abs_path() on the result.  I guess that is
>> because $repo->repo_path() has always been a result of applying the
>> abs_path() function to something, so it was to safeguard the callers
>> that expect an absolute path coming back from hooks_path?
>>
>> And that makes this change dubious, especially as a band-aid for a
>> breakage immediately before the final release, doesn't it?  Are we
>> convinced that the callers are OK with seeing sometimes relative
>> paths?  Certainly the cases the tests J6t fixed are not negatively
>> affected, but is that sufficient?  To what directory is the
>> configuration variable supposed to be relative to, and are we sure
>> that the user will always invoke "git send-email" from that
>> directory?
>
> The one caller is git-send-email.perl is fine with it, at least on *nix,
> this fix still needs testing on Windows.
>
> The repo_path() function was introduced in c8243933c74, so it's never
> been in a release, thus I think it's fine to alter its behavior.
>
> The code here doesn't need to concern itself with what needs to be
> relative to what, you run send-email in some working tree directory (or
> top-level), and depending on core.hooksPath we'll either return a
> relative path to the .git/hooks or an absolute one, the system()
> invocation will accept either.

...I think the one issue with my 2/2 is that it doesn't go far enough,
we should just remove the repo_path() from Git.pm and instead use its:

    $self->command_oneline('rev-parse', '--git-path', 'hooks')

...in the one user in git-send-email.perl, as discussed in other
serieses Git.pm is "public", so stuff we stick in there we can't
alter. In this case we're doing so before a release, and nobody wanted
this except git-send-email.perl.

That caller is likely to just go away if and when Emily's "git hook run"
lands, so I think it would be best (but not strictly needed for the
pre-rc fix) to just remove that API.

What do you / Robert Foss think (maybe he wanted this for something
else...)?