Re: General support for ! in git-config values

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 1, 2012, 22:21 UTC
Message-ID: <7v62fq2o03.fsf@alter.siamese.dyndns.org>
In-Reply-To: <CACBZZX5mX55Rh8b2GYv7wKbCCypCkrn5AiM9BpXydgcYxHWdQA@mail.gmail.com>

Ævar Arnfjörð Bjarmason <avarab@gmail.com> writes:

Show 6 quoted lines

>> I.e., everything pertaining to "!" happens after we get the config
>> string. So what is it that you want "git config --with-exec" to do?
>
> I agree that that's how it should work, I just suggested --with-exec
> in case anyone complained about the backwards compatibility issue of
> changing the meaning of "!" for existing configs.

Now you made me utterly confused.

What "backwards compatibility" issue do you have in mind? If I name myself '!me' with "user.name = !me", do I suddenly break backwards compatibility of Git with previous versions somehow? If so how?

The --with-exec option you talk about seems to me the option about the backward compatibility of the _calling script_ of "git config". The old version of git-blorl script may have used foo.bar as a mere string, but a new version of it may (optionally) interpret foo.bar's value in a special way when it begins with a "!", introducing a backward compatibility issues to git-blorl script, and users who want to take advantage of that feature may want to run it as "git-blorl --with-exec", and the relevant part of the "git-blorl" script might look like this:

	foo_bar=$(git config foo.bar)
        case "$with_exec,$foo_bar" in
        yes,\!*)
        	foo_bar=$(eval ${foo_bar#\!}) ;;
	esac
        ... then do something interesting using $foo_bar ...