+++ This bug was initially created as a clone of Bug #677685 +++

Description of problem:
Koji build of rubygem-actionpack fails while it worked week ago:
https://koji.fedoraproject.org/koji/taskinfo?taskID=2841403
http://koji.fedoraproject.org/koji/buildinfo?buildID=225223

Version-Release number of selected component (if applicable):
mock-chroot> cat /etc/redhat-release 
Fedora release 15 (Rawhide)
mock-chroot> rpm -q patch
patch-2.6.1-8.fc15.x86_64

How reproducible:
mock -r fedora-x86_64 ../SRPMS/rubygem-actionpack-3.0.3-3.fc14.src.rpm

mock-chroot> ls specifications/
actionpack-3.0.3.gemspec
mock-chroot> /usr/bin/patch -s -p0 --fuzz=0 < /builddir/build/SOURCES/actionpack-downgrade-dependencies.patch
mock-chroot> ls specifications/
actionpack-3.0.3.gemspec  actionpack-3.0.3.gemspec.orig


Well, so currently when some hunk is found like:
The text leading up to this was:
--------------------------
|--- specifications/actionpack-3.0.3.gemspec.orig       2011-01-18 16:24:30.469405214 -0500
|+++ specifications/actionpack-3.0.3.gemspec    2011-01-18 16:26:01.445405000 -0500
--------------------------
Patching file specifications/actionpack-3.0.3.gemspec using Plan A...
Hunk #1 succeeded at 26 (offset -1 lines).
done

Actually with --no-backup-if-mismatch option backup file is not created.
However with --posix option backup file is actually created. As far as
I read $ man patch, --posix should behave as the same as 
--no-backup-if-mismatch option is used and no backup file should be created.