How to patch files in a package's debian directory

[Malte Forkel <malte.forkel@berlin.de>]

Hello,

I'm testing some changes to an existing package which is using format
3.0 (quilt). I have split my changes into two patches: One modifies the
original source, one adapts files in the debian directory.

This approach fails when I build the package due to the way dpkg-source
build the source package. As described in dpkg-source(1), it extracts
the original tarball into a temporary directory, copies the existing
debian directory and then applies all patches. But since the files in
debian have already been patched, dpkg-source fails because my second
patch can not be applied twice.

There were three reasons for my approach: I would still like to be able
to build versions of the package without the changes I'm currently
testing. Plus, I would to easily reapply my changes when a new version
of the package is available. And finally, I thought the two patches were
a convenient format for passing along my changes to non-Debian and
Debian users, e.g. to the "upstream packager".

How would you handle this?

Thanks
Malte