perl-PatchReader -- Utilities to read and manipulate patches and CVS
http://search.cpan.org/dist/PatchReader/
PatchReader is a set of utilities for reading in, transforming, and doing
various other things with a patch. It basically allows you to create
a chain of readers that can read a patch, remove files from a patch,
add CVS context, fix up the patch root according to CVS, and output the
patch as raw unified or through a template processor (used in some places
to output a patch as HTML).