It's not necessarily obvious how to perform a mirror, so add a recipe
which tells what git does as well as provide example code of how to
perform the same steps in pygit2.
In b3025e3fe I had written that when following my recipe, the repository
remains in cherry-picking mode afterwards. In issue #516 I was told that
Repository.state_cleanup() is needed to correct that. Therefore add it
to the recipe.
Also add a note near the documentation for cherry-pick, so that nobody
will overlook this again. Apparently there are other times when you need
to do Repository.state_cleanup() as well, but it's not documented, I
don't know when and I don't want to take the time and find out. So leave
it at that for now.
I'm not the guy who looks at examples in the first place and I guess
there are other people like me. When I wanted find out how to get
information out of a Diff, I looked at the documented methods and didn't
find anything. Only later @cmn showed me the [p for p in diff] example
in the documentation. Add a short piece of information that gives a hint
to those who prefer the dry API docs.
Add the way that worked for me. Not sure if it is idiomatic. When doing
the convenience-mode cherry-pick, the repo remains in cherry-picking
mode afterwards. I've already added an issue for this.
The submodule type has been implemented as a C type. When opening
a submodule's repository this leads to the bug that instead of an
actual pygit2.Repository being instantiated we only create an
object of the C Repository type.
As this is not trivially fixed within the C code, reimplement the
submodule type as a Python interface with CFFI. As submodules
provide no functionality that is usually accessed repeatedly the
code paths should not prove performance critical. In addition,
maintainability is improved by this reimplementation.
As @jdavid pointed out, Python 3 already provides a tzinfo subclass for
fixed UTC offsets. Incorporate this in the recipe. Leave the old code
with the self-made class, since many people are working with Python 2
and it is harder to find out there.
