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.
import os
import sys
import time
from mercurial import (
commands,
hg,
pycompat,
ui as uimod,
util,
)
TESTDIR = os.environ["TESTDIR"]
BUNDLEPATH = os.path.join(TESTDIR, 'bundles', 'test-no-symlinks.hg')
# only makes sense to test on os which supports symlinks
if not getattr(os, "symlink", False):
sys.exit(80) # SKIPPED_STATUS defined in run-tests.py
u = uimod.ui.load()
# hide outer repo
hg.peer(u, {}, b'.', create=True)
# unbundle with symlink support
hg.peer(u, {}, b'test0', create=True)
repo = hg.repository(u, b'test0')
commands.unbundle(u, repo, pycompat.fsencode(BUNDLEPATH), update=True)
# wait a bit, or the status call wont update the dirstate
time.sleep(1)
commands.status(u, repo)
# now disable symlink support -- this is what os.symlink would do on a
# non-symlink file system
def symlink_failure(src, dst):
raise OSError(1, "Operation not permitted")
os.symlink = symlink_failure
def islink_failure(path):
return False
os.path.islink = islink_failure
# dereference links as if a Samba server has exported this to a
# Windows client
for f in b'test0/a.lnk', b'test0/d/b.lnk':
os.unlink(f)
fp = open(f, 'wb')
fp.write(util.readfile(f[:-4]))
fp.close()
# reload repository
u = uimod.ui.load()
repo = hg.repository(u, b'test0')
commands.status(u, repo)
# try unbundling a repo which contains symlinks
u = uimod.ui.load()
repo = hg.repository(u, b'test1', create=True)
commands.unbundle(u, repo, pycompat.fsencode(BUNDLEPATH), update=True)