git: initialize `extra` to have at least the branch name for nullid Otherwise, this crashes trying to convert to local encoding: ... File "/mnt/c/Users/Matt/hg/mercurial/logcmdutil.py", line 333, in _show branch = ctx.branch() File "/mnt/c/Users/Matt/hg/mercurial/context.py", line 675, in branch return encoding.tolocal(self._changeset.extra.get(b"branch")) File "/mnt/c/Users/Matt/hg/mercurial/encoding.py", line 181, in tolocal if isasciistr(s): TypeError: a bytes-like object is required, not 'NoneType' This was originally reported to the thg bug tracker. https://foss.heptapod.net/mercurial/tortoisehg/thg/-/issues/5629 Differential Revision: https://phab.mercurial-scm.org/D10528