tests/heredoctest.py

py3: make tests/test-impexp-branch.t compatible with Python 3

This patch adds some missig b'' prefixes and add suppress the output of write()
calls.

Differential Revision: https://phab.mercurial-scm.org/D3789

from __future__ import absolute_import, print_function

import sys

globalvars = {}
lines = sys.stdin.readlines()
while lines:
    l = lines.pop(0)
    if l.startswith('SALT'):
        print(l[:-1])
    elif l.startswith('>>> '):
        snippet = l[4:]
        while lines and lines[0].startswith('... '):
            l = lines.pop(0)
            snippet += l[4:]
        c = compile(snippet, '<heredoc>', 'single')
        try:
            exec(c, globalvars)
        except Exception as inst:
            print(repr(inst))