Subject: Re: [PATCH 0/2] Simplify "commented" API functions

From: Junio C Hamano <[email-masked]>
Date: Fri, 13 Sep 2024 10:23:27 -0700

Patrick Steinhardt <[email-masked]> writes:

> I'm not quite sure I agree. The comment strings we have are in theory
> broken, because they can be configured differently per repository. So if
> you happen to have a Git command that operates on multiple repositories
> at once and that needs to pay attention to that config then it would now
> use the same comment character for both repositories, which I'd argue is
> the wrong thing to do.

Correct.  It needs a move from global to a member in a repository
instance, but the same "hey do not keep passing the same parameter"
motivation behind these patches applies, as the existing call sites
most likely will instead pass "the_repository->comment_line_str" to
these two functions.  The simplification would move that reference
to "the_repository->comment_line_str" down to these two functions.

> The recent patch series that makes "environment.c" aware of
> `USE_THE_REPOSITORY_VARIABLE` already converted some of the global
> config variables to be per-repository, because ultimately all of them
> are broken in the described way. So from my point of view we should aim
> to convert remaining ones to be per-repository, as well.

Yes, I view the environement change somewhat incomplete and it was
annoying to see things other than the_repository itself and those
that implicitly refer to the_repository covered by the CPP macro.

But we need to step back a bit in order to make the environment
change better.  Not everything works inside a repository and you may
not even have a repository but want to refer to a comment character
(say, "git bugreport" run outside a repository, perhaps, and the
bugreport may want to honor end-user configuration for commentChar
to mark its various sections).  Earlier I said it may make sense to
reimplement the global as a member of a repository instance, but
that is not entirely true.  Such a member in a repository struct may
be a good implementation detail for anybody who asks "what comment
character should I be using in the context I am called?", and there
may be "const char *get_comment_line_str(struct repository *)" that
accepts which repository to work with, but such a function would
need to be prepared to work without any repository, working out of
the system and per-user configuration files.

>   - It depends on a repository, but I'd argue it shouldn't such that we
>     can also query configuration in repo-less settings.
>
>   - `prepare_repo_settings()` makes up for a bad calling convention. I
>     think that lazy accessors are way easier to use.
>
> But it is a start, and something we can continue to build on.

Yup.