From mboxrd@z Thu Jan  1 00:00:00 1970
From: Junio C Hamano <gitster@pobox.com>
Subject: Re: General support for ! in git-config values
Date: Wed, 01 Feb 2012 14:21:48 -0800
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Cc: Jeff King <peff@peff.net>, Git Mailing List <git@vger.kernel.org>
To: =?utf-8?B?w4Z2YXIgQXJuZmrDtnLDsA==?= Bjarmason <avarab@gmail.com>
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=C3=86var Arnfj=C3=B6r=C3=B0 Bjarmason <avarab@gmail.com> writes:

>> 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 =3D !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 ol=
d
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 speci=
al
way when it begins with a "!", introducing a backward compatibility iss=
ues
to git-blorl script, and users who want to take advantage of that featu=
re
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=3D$(git config foo.bar)
        case "$with_exec,$foo_bar" in
        yes,\!*)
        	foo_bar=3D$(eval ${foo_bar#\!}) ;;
	esac
        ... then do something interesting using $foo_bar ...