Re: [PATCH] grep: die gracefully when outside repository

From: Junio C Hamano <gitster@pobox.com>
Date: Oct 15, 2023, 17:57 UTC
Message-ID: <xmqq7cnnpy3z.fsf@gitster.g>
In-Reply-To: <20231015032636.GC554702@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes:

> Is it even reasonable for "grep --no-index" to care about leaving the
> tree in the first place? That is, is there a reason we should not allow:
>
>   git grep --no-index foo ../bar

A huge difference between the bare "grep" and "git grep" is that we know the scope of the project tree, so it goes recursive by default. Should the above command line recursively go below ../bar? Would we allow "/" to be given?

I actually do not think these "we are allowing Git tools to be used on random garbage" is a good idea to begin with X-<. If we invented something nice for our variant in "git grep" and wish we can use it outside the repository, contributing the feature to implementations of "grep" would have been the right way to move forward, instead of contaminating the codebase with things that are not related to Git. Whoever did 59332d13 (Resurrect "git grep --no-index", 2010-02-06) should be punished X-<.

Anyway.

2e48fcdb (grep docs: document --no-index option, 2010-02-25) seems to have wanted to explicitly limit the search within the "current directory", and I am fine to keep the search space limited by the cwd. On the other hand, of course, the users can shoot themselves in the foot with "grep -r foo /", so letting them use "git grep" the same way is perhaps OK. Especially if it simplifies the code if we lift the limitation, that is a very tempting thing to do.

> If we want to avoid leaving the current directory, then I think we need
> to be checking much sooner (but again, I would argue that it is not
> worth caring about in no-index mode).