tests/md5sum.py

worker: handle interrupt on windows

After applying suggestions from https://phab.mercurial-scm.org/D1564
to catch all exceptions in the same way I actually broke the handling of
KeyboardInterrupt on windows. The reason is that KeyboardInterrupt doesn't
dervie from Exception, but BaseException:
https://docs.python.org/2/library/exceptions.html starting from python 2.5

Test Plan:
Run hg on windows and ctrl-c during a large update. No random
exceptions from threads surface in the shell. Previously we'd nearly always get
stack traces from some of threads

Run tests ./run-tests.py
[...]
Failed test-convert-svn-encoding.t: output changed
# Ran 622 tests, 41 skipped, 1 failed.
python hash seed: 2962682116

The test failing seems to have nothing to do with the change and fails on base
revision as well

Differential Revision: https://phab.mercurial-scm.org/D1718

#!/usr/bin/env python
#
# Based on python's Tools/scripts/md5sum.py
#
# This software may be used and distributed according to the terms
# of the PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2, which is
# GPL-compatible.

from __future__ import absolute_import

import hashlib
import os
import sys

try:
    import msvcrt
    msvcrt.setmode(sys.stdout.fileno(), os.O_BINARY)
    msvcrt.setmode(sys.stderr.fileno(), os.O_BINARY)
except ImportError:
    pass

for filename in sys.argv[1:]:
    try:
        fp = open(filename, 'rb')
    except IOError as msg:
        sys.stderr.write('%s: Can\'t open: %s\n' % (filename, msg))
        sys.exit(1)

    m = hashlib.md5()
    try:
        for data in iter(lambda: fp.read(8192), b''):
            m.update(data)
    except IOError as msg:
        sys.stderr.write('%s: I/O error: %s\n' % (filename, msg))
        sys.exit(1)
    sys.stdout.write('%s  %s\n' % (m.hexdigest(), filename))

sys.exit(0)