Subject: Re: [PATCH 8/8] refs: check refnames as fully qualified when resolving

From: Jeff King <[email-masked]>
Date: Tue, 30 Apr 2024 06:41:52 -0400

On Tue, Apr 30, 2024 at 06:54:12AM +0200, Patrick Steinhardt wrote:

> > diff --git a/t/t1430-bad-ref-name.sh b/t/t1430-bad-ref-name.sh
> > index 120e1557d7..5fb780cb08 100755
> > --- a/t/t1430-bad-ref-name.sh
> > +++ b/t/t1430-bad-ref-name.sh
> > @@ -400,4 +400,14 @@ test_expect_success 'update-ref refuses non-underscore outside of refs/' '
> >  	test_grep "refusing to update ref with bad name" err
> >  '
> >  
> > +test_expect_success REFFILES 'rev-parse refuses non-pseudoref outside of refs/' '
> > +	git rev-parse HEAD >.git/bad &&
> > +	test_must_fail git rev-parse --verify bad
> > +'
> > +
> > +test_expect_success REFFILES 'rev-parse recognizes non-pseudoref via worktree' '
> > +	git rev-parse HEAD >.git/bad &&
> > +	test_must_fail git rev-parse --verify main-worktree/bad
> > +'
> 
> Are these really specific to the REFFILES backend? I would expect that
> the reftable backend sohuld fail to parse those, too. The fact that we
> write into the repository directly during the test setup doesn't change
> this, because all this patch is about is that we don't want to parse
> random files in the Git repo. And that is something we should want to
> enforce for all backends.

So this is where I will show my ignorance of reftables. I assume it
still has to implement FETCH_HEAD as a file (since it holds extra data).
But does it do the same for other names outside of "refs/"? I am
assuming not in the paragraph below.

I would expect the test to succeed after my patches on any ref backend,
since we'd enforce the syntax outside of the backend-specific code. But
for a backend which does not look for the root name "foo" directly in
.git/, it is not an interesting test. The looked-for name does not
exist for it, so even if we did try the lookup, it would fail. We cannot
distinguish the two cases from the outcome we see.

So I think dropping REFFILES it would still pass, but we are not really
testing anything that interesting for reftables. That said, I would be
OK dropping the REFFILES in the name of simplicity and just documenting
it in the commit message.

-Peff