tests/sitecustomize.py

extdiff: correctly handle deleted subrepositories (issue3153)

Previously, when extdiff was called on two changesets where
a subrepository had been removed, an unexpected KeyError would
be raised.

Now, the missing subrepository will be ignored.  This behavior
mirrors the behavior in diffordiffstat from cmdutil.py line
~1138-1153.  The KeyError is caught and the revision is
set to None.

try/catch of LookupError around matchmod.narrowmatcher and
sub.status is removed, as LookupError is not raised anywhere
within those methods or deeper calls.

import os

if os.environ.get('COVERAGE_PROCESS_START'):
    try:
        import coverage
        import random

        # uuid is better, but not available in Python 2.4.
        covpath = os.path.join(os.environ['COVERAGE_DIR'],
                               'cov.%s' % random.randrange(0, 1000000000000))
        cov = coverage.coverage(data_file=covpath, auto_data=True)
        cov._warn_no_data = False
        cov._warn_unimported_source = False
        cov.start()
    except ImportError:
        pass