py3: replace file() with open() in test-convert-mtn.t
While I was here, I added b'' prefixes to make sure we write things correctly in
bytes mode on Python 3.
Differential Revision: https://phab.mercurial-scm.org/D2111
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))