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.
