Re: [PATCH] make git barf when an alias changes environment variables

What does this patch do when you do this?

	: Because I usually work with this repository...
	$ GIT_DIR=$some_repository
        $ export GIT_DIR

        : Then much later, I happen to visit another repository
        : to take a peek...
	$ cd $somewhere_else
        $ git --git-dir .git some-command

I think --git-dir request on the command line is primarily to
allow overriding whatever the user has in the environment as the
fallback default, so if the patch makes it barf that is not very
nice.