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
Mercurial
=========
Mercurial is a fast, easy to use, distributed revision control tool
for software developers.
Basic install::
$ make # see install targets
$ make install # do a system-wide install
$ hg debuginstall # sanity-check setup
$ hg # see help
Running without installing::
$ make local # build for inplace usage
$ ./hg --version # should show the latest version
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.
Notes for packagers
===================
Mercurial ships a copy of the python-zstandard sources. This is used to
provide support for zstd compression and decompression functionality. The
module is not intended to be replaced by the plain python-zstandard nor
is it intended to use a system zstd library. Patches can result in hard
to diagnose errors and are explicitly discouraged as unsupported
configuration.