Config variables and scripting // was Re: [RFC/PATCH] log: add log.firstparent option

[David Aguilar <davvid@gmail.com>]

On Wed, Jul 22, 2015 at 06:23:44PM -0700, Jeff King wrote:
> This patch adds an option to turn on --first-parent all the
> time, along with the corresponding --no-first-parent to
> disable it.

[Putting on my scripter hat]

I sometimes think, "it would be really helpful if we had a way
to tell Git that it should ignore config variables".

This is especially helpful for script writers.   It's pretty
easy to break existing scripts by introducing new config knobs.

For example, "user.name" and "user.email" can be whitelisted by
the calling script and and everything else would just use the
stock defaults.

That way, script writers don't have to do version checks to
figuring out when and when not to include flags like
--no-first-parent, etc.

Would something like,

	GIT_CONFIG_WHITELIST="user.email user.name" \
	git ...

be a sensible interface to such a feature?
-- 
David