match: strengthen visit_children_set invariant, Recursive means "all files"
My previous interpretation of "Recursive" was too relaxed: I thought it
instructed the caller to do something like this:
> you can stop calling `visit_children_set` because you'll need to descend into
> every directory recursively, but you should still check every file if it
> matches or not
Whereas the real instruction seems to be:
> I guarantee that everything in this subtree matches, you can stop
> querying the matcher for all files and dirs altogether.
The evidence to support this:
- the test actually passes with the stronger invariant, revealing no
exceptions from this rule
- the implementation of `visit_children_set` for `DifferenceMatcher`
clearly relies on this requirement, so it must hold for that not to
lead to bugs.
#!/usr/bin/env python
"""Test the running system for features availability. Exit with zero
if all features are there, non-zero otherwise. If a feature name is
prefixed with "no-", the absence of feature is tested.
"""
import hghave
import optparse
import os
import sys
checks = hghave.checks
def list_features():
for name, feature in sorted(checks.items()):
desc = feature[1]
print(name + ':', desc)
def test_features():
failed = 0
for name, feature in checks.items():
check, _ = feature
try:
check()
except Exception as e:
print("feature %s failed: %s" % (name, e))
failed += 1
return failed
parser = optparse.OptionParser("%prog [options] [features]")
parser.add_option(
"--test-features", action="store_true", help="test available features"
)
parser.add_option(
"--list-features", action="store_true", help="list available features"
)
def _loadaddon():
if 'TESTDIR' in os.environ:
# loading from '.' isn't needed, because `hghave` should be
# running at TESTTMP in this case
path = os.environ['TESTDIR']
else:
path = '.'
if not os.path.exists(os.path.join(path, 'hghaveaddon.py')):
return
sys.path.insert(0, path)
try:
import hghaveaddon
assert hghaveaddon # silence pyflakes
except BaseException as inst:
sys.stderr.write(
'failed to import hghaveaddon.py from %r: %s\n' % (path, inst)
)
sys.exit(2)
sys.path.pop(0)
if __name__ == '__main__':
options, args = parser.parse_args()
_loadaddon()
if options.list_features:
list_features()
sys.exit(0)
if options.test_features:
sys.exit(test_features())
hghave.require(args)