Re: [bug] git log --invert-grep --grep=[sufficiently complicated regex] prints nothing

From: Jeff King <peff@peff.net>
Date: Nov 24, 2022, 16:35 UTC
Message-ID: <Y3+dRELMa8AXZ0tZ@coredump.intra.peff.net>
In-Reply-To: <221124.861qpspckm.gmgdl@evledraar.gmail.com>

On Thu, Nov 24, 2022 at 04:53:28PM +0100, Ævar Arnfjörð Bjarmason wrote:

Show 17 quoted lines

> This doesn't help with your case, but I remember there being some
> similar confusions and/or expectations mismatches reported in the
> patch. E.g. "--since" here:
> https://lore.kernel.org/git/220401.86pmm1nmvh.gmgdl@evledraar.gmail.com/
> 
> I couldn't find a reference quickly, but I seem to recall (but perhaps
> I'm imagining it) that we had a report/discussion semi-recently about:
> 
> 	git log --reverse --follow -- path
> 
> Which has a similar edge case, e.g. try on git.git:
> 
> 	git log --reverse --follow -- object-name.c
> 
> That's also "correct" if you look at it from the POV of how we implement
> it, i.e. we'll traverse, and the rename to object-name.c is the first
> time we encounter the name from the POV of the walking logic.

I think all of this goes back to Linus's original "--follow is a hack I bolted on" implementation. It probably should happen up-front as part of the history simplification. I think it's a combination of nobody wanting to do the work to extract that, and that it may produce less "streaming" output, as we have to do a lot more work before producing the first line of output.

-Peff