hgext/git/gitutil.py

tests: collect all branch creation in one place in test-copies-chain-merge.t

I found this test case really hard to read because it requires
scrolling back and forth between the setup and the verification. The
next patch will move the verification close to the merge commits they
test. This patch prepares for that by moving all branch creation first
so they are separate from the merge commits (because many merge
commits reuse the same branches).

Differential Revision: https://phab.mercurial-scm.org/D8376

"""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)