All functionality should be available in pure Python. Optional C
implementations may be written for performance reasons, but should never
replace the Python implementation. The C implementations should follow the
kernel/git coding style.

Where possible include updates to NEWS along with your improvements.

New functionality and bug fixes should be accompanied by matching unit tests.

Coding style
------------
Where possible, please follow PEP8 with regard to coding style.

Furthermore, triple-quotes should always be """, single quotes are ' unless
using " would result in less escaping within the string.

Public methods, functions and classes should all have doc strings. Please use
epydoc style docstrings to document parameters and return values.
You can generate the documentation by running "make doc".

Running the tests
-----------------
To run the testsuite, you should be able to simply run "make check". This
will run the tests using unittest.

::
   $ make check

Tox configuration is also present as well as a Travis configuration file.

String Types
------------
Like Linux, Git treats filenames as arbitrary bytestrings. There is no prescribed
encoding for these strings, and although it is fairly common to use UTF-8, any
raw byte strings are supported.

For this reason, Dulwich internally treats git-based filenames as bytestrings.
It is up to the Dulwich API user to encode and decode them if necessary. In the
future, the porcelain may accept unicode strings and convert them to bytestrings
as necessary on the fly (using sys.getfilesystemencoding()).

* git-repository related filenames: bytes
* object sha1 digests (20 bytes long): bytes
* object sha1 hexdigests (40 bytes long): str (bytestrings on python2, strings
  on python3)

Merge requests
--------------
Please either send pull requests to the maintainer (jelmer@jelmer.uk) or create
new pull requests on GitHub.

Licensing
---------
All contributions should be made under the same license that Dulwich itself
comes under: both Apache License, version 2.0 or later and GNU General Public
License, version 2.0 or later.