From: Jakub Narebski Date: Wed, 21 Nov 2007 18:47:50 GMT Subject: Re: [PATCH] autoconf: Add tests for memmem, strtoumax and mkdtemp functions Message-ID: <200711211947.50661.jnareb@gmail.com> In-Reply-To: <20071121065858.GU14735@spearce.org> Shawn O. Pearce wrote: > Jakub Narebski wrote: >> 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. Can you write a short program which demonstrates this error (either fails with some error code, or produces wrong output)? That would be enough for configure.ac (see for example NO_C99_FORMAT in configure.ac) Unless this is Schroedinger bug... -- Jakub Narebski Poland