On Thu, May 01, 2025 at 02:40:56PM -0700, Junio C Hamano wrote: > 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 or > an empty file is not even seen. > > cf. <xmqq5ywehb69.fsf@gitster.g> > > Signed-off-by: Junio C Hamano <gitster@xxxxxxxxx> > --- > Documentation/config.txt | 5 ++++- > config.c | 16 ++++++++++++++-- > t/t7500-commit-template-squash-signoff.sh | 9 +++++++++ > 3 files changed, 27 insertions(+), 3 deletions(-) > > diff --git a/Documentation/config.txt b/Documentation/config.txt > index 8c0b3ed807..199e29ccea 100644 > --- a/Documentation/config.txt > +++ b/Documentation/config.txt > @@ -358,7 +358,10 @@ compiled without runtime prefix support, the compiled-in prefix will be > substituted instead. In the unlikely event that a literal path needs to > be specified that should _not_ be expanded, it needs to be prefixed by > `./`, like so: `./%(prefix)/bin`. > - > ++ > +If prefixed with `:(optional)`, the configuration variable is treated > +as if it does not exist, if the named path does not exist or names an > +empty file. I can see why it may be useful to allow for non-existent paths. But I wonder whether we really should be skipping over empty files, as well, as it may be assuming too much about the semantics of a given config key. In other words, are we reasonably sure that there won't ever be a usecase where you may want to specify an optional and empty file? And are there any use cases where an empty file should be ignored? Patrick
