working on a 2.5.6pre1 release

[Dave Dykstra]

I'm working on trying to get rsync 2.5.6pre1 available for people to
test more widely.  I'm out of time for today, and I'm stuck on a problem
that some machines on build.samba.org are showing on the 'chgrp' test.
I can reproduce this on my home redhat 7.3 system too.  It appears to be a
timing problem because when I do strace -F -f on it the problem goes away.
Everything seems to go through normally but then it exits with an exit
code of 12, I think because the child receiver process is terminated with
a SIGUSR2 which is signal 12 and because the bug that was preventing exit
codes from being properly reported from children has now been fixed.
It's very hard to debug because it is a timing problem and because it
happens after rprintf handling is already shut down in the child process.
I suspected that maybe the catching of the SIGUSR2 signal was not getting
inherited from its parent, but it doesn't help to re-set it in the child.
Nevertheless, I'm not sure whether or not the sigusr2_handler function
is getting called in the child.  I'd appreciate some help with this if
anybody else thinks they can figure it out.

- Dave Dykstra