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
#!/usr/bin/env python
from __future__ import absolute_import
__doc__ = """Same as `echo a >> b`, but ensures a changed mtime of b.
Without this svn will not detect workspace changes."""
import os
import sys
text = sys.argv[1]
fname = sys.argv[2]
f = open(fname, "ab")
try:
before = os.fstat(f.fileno()).st_mtime
f.write(text)
f.write("\n")
finally:
f.close()
inc = 1
now = os.stat(fname).st_mtime
while now == before:
t = now + inc
inc += 1
os.utime(fname, (t, t))
now = os.stat(fname).st_mtime