Re: [PATCH] autoconf: Add tests for memmem, strtoumax and mkdtemp functions

From: Shawn O. Pearce <spearce@spearce.org>
Date: Nov 21, 2007, 06:58 UTC
Message-ID: <20071121065858.GU14735@spearce.org>
In-Reply-To: <200711191947.05960.jnareb@gmail.com>

Jakub Narebski <jnareb@gmail.com> wrote:

Show 7 quoted lines

> By the way, do you have idea how to test for the following
> in configure.ac:
> 
> * Define NO_PREAD if you have a problem with pread() system call (e.g.
>   cygwin.dll before v1.5.22).
> 
>   - what is the problem? how to detect it?

This also appears to be broken on HP-UX (e.g. we need to set NO_PREAD there). Thiago on IRC talked about this the other day when he was trying to build git on a bunch of different systems.

Unfortunately this may just need to be an OS based test. The code compiles just fine but when index-pack tries to use pread to walk back through the deltas and generate their SHA-1s it barfs without an error code. I suspect the failure is pread claiming it put the data into the user buffer but not actually doing so, which causes zlib's inflate() to then see data corruption.

Ouch.

-- 
Shawn.