Subject: Re: [PATCH v2 2/4] ref: add regular ref content check for files backend

From: Patrick Steinhardt <[email-masked]>
Date: Thu, 29 Aug 2024 12:19:13 +0200

On Wed, Aug 28, 2024 at 09:32:16AM -0700, Junio C Hamano wrote:
> Patrick Steinhardt <[email-masked]> writes:
> 
> >> Git 3.0 boundary might be a good time to tighten interoperability
> >> rules such that we won't accept anything we wouldn't have written
> >> ourselves (not limited to loose ref format, but this applies to
> >> anything on-disk or on-wire), but we'd need enough preparation if we
> >> want to be able to do so in the future.
> >
> > I quite like this idea.
> 
> I wouldn't say that I wrote it as a devil's advocate comment, but I
> was hoping that somebody quote Postel in response, as the above
> advocates a directly opposite position, which I wouldn't usually
> take.

For context, this is the quote you probably refer to: "be conservative
in what you do, be liberal in what you accept from others".

In any case, I still think it is sensible to at least warn about refs
like this. It is unexpected to me and may indicate real issues in the
understanding of others that end up writing to the refdb. If there are
implementations of Git out there that intentionally use our lax parsing
to e.g. stuff additional metadata into refs, then we need to tell them
that this is not okay.

This may have been fine in the past where there was only a single ref
backend, but now with multiple ref backends the picture has changed in
my opinion.

Patrick