Re: Fwd: coverity problems in reftable code

From: Jeff King <peff@peff.net>
Date: Dec 8, 2021, 19:12 UTC
Message-ID: <YbEDnfZgeQZp6JJj@coredump.intra.peff.net>
In-Reply-To: <CAFQ2z_NUCj00981oQiswaYTK6iJ=HuPjNGP46tLL-RGL2xHbEw@mail.gmail.com>

On Wed, Dec 08, 2021 at 11:50:16AM +0100, Han-Wen Nienhuys wrote:

Show 5 quoted lines

> > Summary is below, but I'm not sure it's that useful without the whole
> > code flow. The unreachable-code one seems just wrong. We can get there
> > via the "goto done" in the BLOCK_TYPE_LOG conditional, it looks like.
> 
> they're all valid. There is a shadowed variable in the unreachable code one.

Ah, good catch. Yes, that is definitely the problem.

Show 7 quoted lines

> > The first FORWARD_NULL doesn't look obvious to me from the code. But it
> > triggers a segfault running "test-tool reftable". (It didn't immediately
> > for me on Linux, but Windows CI shows it, and compiling with ASan on
> > Linux does too).
> 
> yeah, that must be the problem on windows too. The 3rd test case
> passes NULL into memcmp() with a 0 length.

Ah, makes sense. I didn't look closely, but that would explain perfectly why it fails on some platforms but not others.

> I've folded in your patch and fixed the issues.

Thanks!

-Peff