git: don't fail import when pygit2 is not install
`test-duplicateoptions.py` was failing on py2 for be because I didn't
have pygit2 installed. It failed because we depend on pygit2 at import
time. This patch makes it so we successfully load the git extension
even if pygit2 doesn't exist -- we just won't be able to use it in
that case.
Differential Revision: https://phab.mercurial-scm.org/D8268
"""utilities to assist in working with pygit2"""
from __future__ import absolute_import
from mercurial.node import bin, hex, nullid
from mercurial import pycompat
pygit2_module = None
def get_pygit2():
global pygit2_module
if pygit2_module is None:
try:
import pygit2 as pygit2_module
pygit2_module.InvalidSpecError
except (ImportError, AttributeError):
pass
return pygit2_module
def togitnode(n):
"""Wrapper to convert a Mercurial binary node to a unicode hexlified node.
pygit2 and sqlite both need nodes as strings, not bytes.
"""
assert len(n) == 20
return pycompat.sysstr(hex(n))
def fromgitnode(n):
"""Opposite of togitnode."""
assert len(n) == 40
if pycompat.ispy3:
return bin(n.encode('ascii'))
return bin(n)
nullgit = togitnode(nullid)