Re: [PATCH] grep: remove "repo" arg from non-supporting funcs

From: Jonathan Tan <jonathantanmy@google.com>
Date: Mar 28, 2018, 00:24 UTC
Message-ID: <20180327172451.34f60c483133df629b1e8ec6@google.com>
In-Reply-To: <CAGZ79kY-E5FZRJAg6QG0DX1TzWXgo9LqJ-b7JojpkD6_BdF-wQ@mail.gmail.com>

On Tue, 27 Mar 2018 16:20:25 -0700 Stefan Beller <sbeller@google.com> wrote:

Show 19 quoted lines

> On Tue, Mar 27, 2018 at 3:58 PM, Jonathan Tan <jonathantanmy@google.com> wrote:
> > As part of commit f9ee2fcdfa ("grep: recurse in-process using 'struct
> > repository'", 2017-08-02), many functions in builtin/grep.c were
> > converted to also take "struct repository *" arguments. Among them were
> > grep_object() and grep_objects().
> >
> > However, at least grep_objects() was converted incompletely - it calls
> > gitmodules_config_oid(), which references the_repository.
> >
> > But it turns out that the conversion was extraneous anyway - there has
> > been no user-visible effect - because grep_objects() is never invoked
> > except with the_repository.
> >
> > Revert the changes to grep_objects() and grep_object() (which conversion
> > is also extraneous) to show that both these functions do not support
> > repositories other than the_repository.
> 
> I'd rather convert gitmodules_config_oid instead of reverting the other
> functions into a world without an arbitrary repository object.

I don't really think of it as a reversion, since grep_objects() didn't fully support repos other than the_repository anyway.

Besides that, that's fine, but then:

 (1) You would have to explain both in the gitmodules_config_oid() and
     in this patch why "gitmodules_config_oid(...)" ->
     "gitmodules_config_oid(repo, ...)" and "submodule_free()" ->
     "submodule_free(repo)" are safe, since they have different behavior
     upon first glance. (They have the same behavior only because
     grep_objects() is always called with the_repository.) I was trying
     to explain this in as clear a way as possible, by showing (with
     code) that grep_objects() only works with, and is only called with,
     the_repository.
 (2) The code path where repo != the_repository would still never be
     exercised, and I prefer to not have such code paths.

I don't feel too strongly about (1), since they just concern commit messages, of which there are many valid opinions on how to write them. I feel a bit more strongly about (2), but can concede my point if the project is OK with a code path not being exercised.

> Thanks for looking at the patches!
> I'd think this patch is orthogonal to the series, as this is about the effort
> of converting parts of git-grep whereas this series is fixing a bug (by
> converting parts of the submodule config machinery))?

It is orthogonal in the same way as your patch 1/5, I think - a preparatory patch to make your "real" patches easier to understand.