From: D. Ben Knoble <ben.knoble+github@gmail.com>
Date: Sun, 02 Nov 2025 16:20:30 GMT
Subject: Re: [PATCH v2 2/3] config: values of pathname type can be prefixed with :(optional)
Message-ID: <CALnO6CC02MDThBJZg47ecZQnzdEE+tXPBcNzregduPvgkASceg@mail.gmail.com>
In-Reply-To: <a687ec17-8ee4-428e-bae5-063716d59a08@gmail.com>

Hi Phillip

On Tue, Sep 30, 2025 at 11:26 AM Phillip Wood <phillip.wood123@gmail.com> wrote:
>
> Hi Ben
>
> On 28/09/2025 22:29, D. Ben Knoble wrote:
> > From: Junio C Hamano <gitster@pobox.com>
> >
> > Sometimes people want to specify additional configuration data
> > as "best effort" basis.  Maybe commit.template configuration file points
> > at somewhere in ~/template/ but on a particular system, the file may not
> > exist and the user may be OK without using the template in such a case.
> >
> > When the value given to a configuration variable whose type is
> > pathname wants to signal such an optional file, it can be marked by
> > prepending ":(optional)" in front of it.  Such a setting that is
> > marked optional would avoid getting the command barf for a missing
> > file, as an optional configuration setting that names a missing
> > file is not even seen.
>
> I think this would be a useful addition, we've had several people
> wanting to make blame.ignoreRevsFile optional and this provides a
> general way to do that.
>
> > --- a/config.c
> > +++ b/config.c
> > @@ -1279,11 +1279,23 @@ int git_config_string(char **dest, const char *var, const char *value)
> >
> >   int git_config_pathname(char **dest, const char *var, const char *value)
> >   {
> > +     int is_optional;
>
> This could be bool rather than int, the rest of the implementation looks
> good.

Agreed. For now I've split this change and the parseopt change to bool
as separate commits, but I'm indifferent to making them a single
change.

>
> > --- a/t/t7500-commit-template-squash-signoff.sh
> > +++ b/t/t7500-commit-template-squash-signoff.sh
> > @@ -46,6 +46,15 @@ commit_msg_is ()
> >       )
> >   '
> >
> > +test_expect_success 'nonexistent optional template file in config' '
> > +     test_config commit.template ":(optional)$PWD"/notexist &&
> > +     (
> > +             GIT_EDITOR="echo hello >\"\$1\"" &&
>
> when git runs the editor this will be expanded to
>
>      sh -c 'echo hello >"$1" "$@"' 'echo hello >"$1"' path/to/file
>
> I think it should be
>
>      GIT_EDITOR="echo hello >"
>
> instead
> > +             export GIT_EDITOR &&
> > +             git commit --allow-empty
>
> Maybe I'm missing something but don't we want to ensure that we have a
> non-empty message here? Also as it is a single command we can avoid the
> subshell with
>
>      GIT_EDITOR="echo hello >" git commit
>
> Thanks
>
> Phillip

Great catch, thanks. I've certainly had some trouble with this
expansion before [1]. It looks like this has been fixed in the version
that was merged, so I'll avoid touching it further for now. And thanks
also to Junio for the updates here.

[1]: