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
"""
Tests the behavior of filelog w.r.t. data starting with '\1\n'
"""
from mercurial.node import hex
from mercurial import (
hg,
ui as uimod,
)
myui = uimod.ui.load()
repo = hg.repository(myui, path=b'.', create=True)
fl = repo.file(b'foobar')
def addrev(text, renamed=False):
if renamed:
# data doesn't matter. Just make sure filelog.renamed() returns True
meta = {b'copyrev': hex(repo.nullid), b'copy': b'bar'}
else:
meta = {}
lock = t = None
try:
lock = repo.lock()
t = repo.transaction(b'commit')
node = fl.add(text, meta, t, 0, repo.nullid, repo.nullid)
return node
finally:
if t:
t.close()
if lock:
lock.release()
def error(text):
print('ERROR: ' + text)
textwith = b'\1\nfoo'
without = b'foo'
node = addrev(textwith)
if not textwith == fl.read(node):
error('filelog.read for data starting with \\1\\n')
if fl.cmp(node, textwith) or not fl.cmp(node, without):
error('filelog.cmp for data starting with \\1\\n')
if fl.size(0) != len(textwith):
error(
'FIXME: This is a known failure of filelog.size for data starting '
'with \\1\\n'
)
node = addrev(textwith, renamed=True)
if not textwith == fl.read(node):
error('filelog.read for a renaming + data starting with \\1\\n')
if fl.cmp(node, textwith) or not fl.cmp(node, without):
error('filelog.cmp for a renaming + data starting with \\1\\n')
if fl.size(1) != len(textwith):
error('filelog.size for a renaming + data starting with \\1\\n')
print('OK.')