Re: [PATCH] config: add an includeIf.env{Exists,Bool,Is,Match}

[Jeff King <peff@peff.net>]

On Tue, Sep 28, 2021 at 04:42:51AM +0200, Ævar Arnfjörð Bjarmason wrote:

> > A perhaps more subtle but less awkward to type version is to just
> > require two arguments, like:
> >
> >   git --config <key> <value> ...
> 
> I suppose --config would work like that, you can'd to it with "-c". I
> think it's more confusing to have a "-c" and "--config" which unlike
> most other things don't follow the obvious long and short option names
> working the same way.

Yeah, probably "--config-pair" or something might be less confusing.
Anyway...

> > but I'd just as soon continue to leave it un-implemented if nobody has
> > actually needed it in practice.
> 
> *nod*. I do think it's bad design to introduce an "env" inclusion
> feature that relies on "=" though while we don't have something like
> that, i.e.
> 
> I think we should probably not add that --config-{key,value}, but
> avoiding the arbitrary limitation of not being able to specify certain
> config keys seems prudent in that case, and since the "=" v.s. ":" is
> only an aesthetic preference I think being able to compose things
> without limitations wins out.

I don't really agree with that. Whatever syntax we use now, we'll be
stuck with forever. It seems a shame to predicate that choice only on
the "-c doesn't support =" thing that nobody has actually run across in
practice (and I don't think is something people will run into with
this).

> We do have the "=" key limitation now, but I don't think it's there for
> any key we currently define, except things like "url.<base>.insteadOf"
> if the "<base> has a "=" in it (and maybe just that one).

It's really a potential problem for any 3-level config key. So urls,
branch names, remote names, various tool names, filter/diff drivers,
existing includeIf conditions. This might be the first one where we
really _encourage_ the use of "=" signs, but it still strikes me as
weird that you'd want to do so on the command-line in practice.

-Peff