Re: Breakage (?) in configure and git_vsnprintf()

From: Michael Haggerty <mhagger@alum.mit.edu>
Date: Dec 12, 2011, 10:25 UTC
Message-ID: <4EE5D694.7040407@alum.mit.edu>
In-Reply-To: <20111212064305.GA16511@sigill.intra.peff.net>

On 12/12/2011 07:43 AM, Jeff King wrote:

Show 12 quoted lines

> On Sun, Dec 11, 2011 at 07:42:03PM +0100, Michael Haggerty wrote:
>> 2. The configure problem causes git_vsnprintf() to be wrapped around the
>> C library version.  This leads to many failures in the test suite.  I
>> suppose that git_vsnprintf() is broken in some way.
> 
> I enabled SNPRINTF_RETURNS_BOGUS manually and was able to see the test
> suite failures. Very oddly, I could get them while running the full
> suite in parallel, but when I ran individual scripts, the problem went
> away. Which makes no sense to me at all.
> 
> However, I peeked at the git_vsnprintf function, and one obvious error
> is that it calls vsnprintf multiple times on the same va_list.

Thanks for the quick response! Yes, I think you've hit the nail on the head. (Though I think Andreas is correct that va_end() needs to be called on the copies.) Either with or without va_end(), your patch fixes the test suite failures for me.

> I'll leave the issue of "-std=c89" triggering SNPRINTF_RETURNS_BOGUS to
> people who know and care about autoconf. My gut is to say "don't do
> that". Git is not actually pure c89. [...]

OK, I can live with that. Poor Junio will probably be stuck correcting my non-c89isms again, though :-(

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu
http://softwareswirl.blogspot.com/