httppeer: avoid another bad reference before assignment warning
This wasn't a problem, because `b''` from the `AttributeError` handler is in
`bundle2.bundletypes`, so the following loop and conditional always run at least
once. But PyCharm can't figure that out on its own, and it took a little
exploring to figure out it wasn't a problem. The usage in `bundle2.writebundle`
is to look it up in the map of bundle types, so it will break in a more obvious
way in the unlikely event that the empty string is removed from the map in the
future.
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.