Re: Unexpected (bug-like) behavior in `git ls-remote` matching.

From: Junio C Hamano <gitster@pobox.com>
Date: Feb 9, 2023, 19:43 UTC
Message-ID: <xmqq357eocah.fsf@gitster.g>
In-Reply-To: <Y+Tx3Z45SlMJqDfh@coredump.intra.peff.net>

Jeff King <peff@peff.net> writes:

Show 9 quoted lines

>> I would not recommend sending over regex as protocol capability the
>> same way as ref-prefix works, unless we adopt something that can
>> match linear-time like re2 and use it everywhere, as you can send a
>> pattern that is deliberately made inefficient to inconvenience the
>> other side.
>
> Yeah, I should not even have mentioned regex. It was really meant as "if
> you really wanted to go wild, you could do something as crazy as
> regexes".

The cautionary comment wasn't meant for you (you know I know you better than that by now) but was primarily to deter those who are reading from sidelines from going wild for "low hanging fruit".

Unlike normal desktop features, a feature that can easily be abused for DoS cannot be initially built in a way that is inefficient, with a hope that we will iterate and improve over time, until which time we ship it labeled as "experimental".

> But I would hold off on all of that until somebody has a concrete case
> that shows why their preferred matching scheme is useful.

True, too.

Thanks.