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

Jakub Narebski [off-list ref] 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.

Ouch.

-- 
Shawn.