Re: [RFC PATCH 6/6] hex: allow only lowercase object IDs in breaking changes mode

From: Junio C Hamano <gitster@pobox.com>
Date: Aug 4, 2026, 19:32 UTC
Message-ID: <xmqqldalvfzx.fsf@gitster.g>
In-Reply-To: <am_AL9dymrkidizF@fruit.crustytoothpaste.net>

"brian m. carlson" <sandals@crustytoothpaste.net> writes:

> Postel's Law was a great idea on the early Internet, but it is
> unfortunately no longer a good idea.  The problem is that being liberal
> in what you accept these days usually has security implications.

I am afraid that is debatable, though.

I would grant you that you can increase the attack surface by being carelessly liberal. Recall my example of allowing mixed-case names for loose object files and storing them verbatim on a case-sensitive filesystem without normalizing the names; that is an example of being carelessly liberal.

But is it a good excuse to give up being careful, declare it is impossible to be careful enough, and punt?

Will queue, but I invite others to chime in. My practical side says we should just take the series as it is much less work for us to declare that any incompatibility fallout is the problem of other people who have reimplementations of Git, but my more principled side feels dirty, just for saying this ;-).

Thanks.