tests/filterpyflakes.py

run-tests: do not inherit file descriptor when running a command

This is one of the difference between python2 and python3 and could have been a
reason why test hang with python2 + chg. This does not seems to help the
hanging issue at all…

However, now that this is written lets reduce the difference between python2
and python3.

Differential Revision: https://phab.mercurial-scm.org/D11226

#!/usr/bin/env python3

# Filter output by pyflakes to control which warnings we check

from __future__ import absolute_import, print_function

import re
import sys

lines = []
for line in sys.stdin:
    # We blacklist tests that are too noisy for us
    pats = [
        r"undefined name 'WindowsError'",
        r"redefinition of unused '[^']+' from line",
        # for cffi, allow re-exports from pure.*
        r"cffi/[^:]*:.*\bimport \*' used",
        r"cffi/[^:]*:.*\*' imported but unused",
    ]

    keep = True
    for pat in pats:
        if re.search(pat, line):
            keep = False
            break  # pattern matches
    if keep:
        fn = line.split(':', 1)[0]
        f = open(fn)
        data = f.read()
        f.close()
        if 'no-' 'check-code' in data:
            continue
        lines.append(line)

for line in lines:
    sys.stdout.write(line)
print()