Re: [PATCH v5 1/4] git: make super-prefix option

From: Jeff King <peff@peff.net>
Date: Sep 29, 2016, 18:39 UTC
Message-ID: <20160929183940.vgac7by74gmglaf2@sigill.intra.peff.net>
In-Reply-To: <1475099443-145608-2-git-send-email-bmwill@google.com>

On Wed, Sep 28, 2016 at 02:50:40PM -0700, Brandon Williams wrote:

Show 6 quoted lines

> Add a super-prefix environment variable 'GIT_INTERNAL_SUPER_PREFIX'
> which can be used to specify a path from above a repository down to its
> root.  The immediate use of this option is by commands which have a
> --recurse-submodule option in order to give context to submodules about
> how they were invoked.  This option is currently only allowed for
> builtins which support a super-prefix.

What about non-builtins?

E.g., what should

  git --super-prefix=foo bar

do? Should the externals and scripts check the presence of GIT_INTERNAL_SUPER_PREFIX and barf if it is set? Most scripts would probably notice eventually when calling some other builtin that doesn't support SUPER_PREFIX, but it seems hacky to count on that.

There's also the question of 3rd-party programs. If we want to be conservative, I think you'd want to just always bail in execv_dashed_external() if --super-prefix is in use. That doesn't give an option for scripts to say "hey, I support this", but we can perhaps worry about loosening later.

-Peff