dep3 parser/generator for git-buildpackage

[Thomas Koch]

Hi,

I wrote a dep3 parser / generator to enhance the patch queue handling of git-
buildpackage. The module (and a test module) currently lives here:

https://github.com/thkoch2001/python-
debian/blob/thkoch/dep3_patch/lib/debian/dep3_patch.py

I intend to prepare some commits to git-buildpackage including the module 
there first to let it mature and later include it in python-debian. In git-
buildpackage I'd rewrite / delete some code related to git-pq to let it use 
the new module.

My motivation for writing this was that the git-buildpackage version in 
unstable did not preserve the dep3 header fields during an import-export 
cycle.

The dep3 module does not intend to retain a patch header verbatim. It would be 
a huge effort to do so with little benefit. After a parse-format cycle the 
following will have changed:

- The formatter outputs the fields in a fixed order regardless of the original 
order.
- The formatter outputs the description fields always as continuation fields 
with one space indentation. It does parse but not generate unindented 
description lines.
- The formatter outputs field names in lowercase regardless of the original 
case.

The module does not support dpatch, only quilt.
I'm aware of the deb822 module in python-debian but it is rather hard to 
understand, provides more than needed and might fail to parse unindented 
description lines.

I intend that gbp-pq would create commit messages that conform to the dep3 
specification i.e. I can use the parser to parse the patch header as well as 
the commit message.

Is this OK with you, Guido, Markus? I'm relatively new to python and 
appreciate any review.

Regards,

Thomas Koch, http://www.koch.ro