Re: [PATCH 3/3] builtin/grep: allow implicit --no-index

Thomas Gummerer [off-list ref] writes:

On 01/11, Duy Nguyen wrote:

quoted

On Sun, Jan 10, 2016 at 9:19 PM, Thomas Gummerer [off-list ref] wrote:

quoted

Currently when git grep is used outside of a git repository without the
--no-index option git simply dies.  For convenience, implicitly make git
grep behave like git grep --no-index when it is called outside of a git
repository.

Should we have a line about this behavior in git-grep.txt, maybe the
description section?

Yes good point, the behavior change should definitely be documented.

quoted

I wonder if anybody wants the old behavior (e.g.
non-zero exit code when running outside a repo). If there is such a
case (*), we may need an option to revert it back (--no-no-index seems
ridiculous, maybe --use-index). The safest way though, is introduce a
new option like --use-index=<always|optional|never> then you can make
an grep alias with --use-index=optional.

You're right.  I couldn't think of a reason why someone would rely on
the old behavior, but maybe I missed something.  I like the idea of
introducing the --use-index=... option.

I don't like that, though ;-)

"We run 'git grep' in random places and relied on it to fail when
run in somewhere not under control of Git." feels so flawed at
multiple levels that I doubt it deserves to be kept working.  For
one thing, "git grep" is not the way to tell something is under
control of Git (rev-parse would be a better thing for scriptor to
use).  For another, how would such a script tell between "not a
git repository" and there was no hits?

So I do agree that automatic fallback needs to be documented and
advertised as a feature (or even a bugfix), I do not think we want
to add knobs to keep such a broken script working.

How should we handle priority between --no-index and --use-index,
should we just give --no-index priority if it is set and ignore the
new --use-index option, or is there some other way?

quoted

(*) I've been hitting really weird real-world use cases so I'm a bit paranoid..
--
Duy