py3: add "b" prefix to string literals related to module policy String literals without explicit prefix in __init__.py and policy.py are treated as unicode object on Python3, because these modules are loaded before setup of our specific code transformation (the later module is imported at the beginning of __init__.py). BTW, "modulepolicy" in __init__.py is initialized by "policy.policy". This causes issues below; - checking "policy" value in other modules causes unintentional result For example, "b'py' not in (u'c', u'py')" returns True unintentionally on Python3. - writing "policy" out fails at conversion from unicode to bytes 62939e0148f1 fixed this issue for default code path, but "policy" can be overridden by HGMODULEPOLICY environment variable (it should be rare case for developer using Python3, though). This patch does: - add "b" prefix to all string literals, which are related to module policy, in modules above. - check existence of HGMODULEPOLICY, and overwrite "policy" only if it exists For simplicity, this patch omits checking "supports_bytes_environ", switching os.environ/os.environb, and so on (Yuya agreed this in personal talking)

#require py3exe

This test helps in keeping a track on which commands we can run on
Python 3 and see what kind of errors are coming up.
The full traceback is hidden to have a stable output.

  $ for cmd in version debuginstall ; do
  >   echo $cmd
  >   $PYTHON3 `which hg` $cmd 2>&1 2>&1 | tail -1
  > done
  version
  warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  debuginstall
  no problems detected

  $ cat > included-hgrc <<EOF
  > [extensions]
  > babar = imaginary_elephant
  > EOF
  $ cat >> $HGRCPATH <<EOF
  > %include $TESTTMP/included-hgrc
  > EOF
  $ $PYTHON3 `which hg` version | tail -1
  *** failed to import extension babar from imaginary_elephant: *: 'imaginary_elephant' (glob)
  warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Test bytes-ness of policy.policy with HGMODULEPOLICY

  $ HGMODULEPOLICY=py
  $ export HGMODULEPOLICY
  $ $PYTHON3 `which hg` debuginstall 2>&1 2>&1 | tail -1
  no problems detected