hgext/__init__.py

patch: stop using cext.diffhelpers

The C implementation has a couple of memory bugs, and lacks error handling
which could lead to SEGV. I could fix them one by one (and I mostly finished
that), but the performance gain provided by cext.diffhelper is quite low.
Besides, diffhelpers.addlines() calls back Python, linereader.readline(),
from the innermost loop.

  $ hg export -R mozilla-central 0:100 > patch
  $ ls -lh patch
  -rw-r--r--  184M  patch
  $ hg init repo && hg -R repo import patch --time --bypass
  (cext) time: real 34.970 secs (user 32.720+0.000 sys 2.230+0.000)
  (pure) time: real 35.950 secs (user 33.600+0.000 sys 2.330+0.000)

So, let's simply use the pure Python implementation.

from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)