mail: always fall back to iso-8859-1 if us-ascii won't work (BC) It looks like this was a well-intentioned backwards compat hack for previewing the output of `hg email` in a stable way. Unfortunately I think this hack's time has come, because Python 3 does a much better job of ensuring it actually emits *valid* email messages. In particular, Python 2 would blindly trust us that the bytes we handed it were valid for the encoding we claimed, but Python 3 has some more sniff-tests that we end up failing. As a result, if we're going to print an email to the terminal, try us-ascii first, but if that fails go straight to iso-8859-1 which should be reasonably readable for ascii-compatible patch bodies. This *will* be a breaking change for ascii-incompatible textual patch content, but I don't think that's avoidable if we want to continue using the email library from the stdlib. .. bc:: Emails from the patchbomb extension will always be printed as though they are iso-8859-1 if they're not valid us-ascii. Previously, previewed emails were always claimed to be us-ascii and might contain invalid byte sequences. Differential Revision: https://phab.mercurial-scm.org/D4231

#!/usr/bin/env python
#
# mercurial - scalable distributed SCM
#
# Copyright 2005-2007 Matt Mackall <mpm@selenic.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import

import os
import sys

if os.environ.get('HGUNICODEPEDANTRY', False):
    try:
        reload(sys)
        sys.setdefaultencoding("undefined")
    except NameError:
        pass

libdir = '@LIBDIR@'

if libdir != '@' 'LIBDIR' '@':
    if not os.path.isabs(libdir):
        libdir = os.path.join(os.path.dirname(os.path.realpath(__file__)),
                              libdir)
        libdir = os.path.abspath(libdir)
    sys.path.insert(0, libdir)

# enable importing on demand to reduce startup time
try:
    if sys.version_info[0] < 3 or sys.version_info >= (3, 6):
        import hgdemandimport; hgdemandimport.enable()
except ImportError:
    sys.stderr.write("abort: couldn't find mercurial libraries in [%s]\n" %
                     ' '.join(sys.path))
    sys.stderr.write("(check your install and PYTHONPATH)\n")
    sys.exit(-1)

from mercurial import dispatch
dispatch.run()