tests/test-symlink-os-yes-fs-no.py

repoview: have unfilteredpropertycache using the underlying cache

A  `unfilteredpropertycache` is a kind of `propertycache` used on `localrepo` to
unsure it will always be run against unfiltered repo and stored only once.

As the cached value is never stored in the repoview instance, the descriptor
will always be called. Before this patch such calls always result in a call to
the `__get__` method of the `propertycache` on the unfiltered repo. That was
recomputing a new value on every access through a repoview.

We can't prevent the repoview's `unfilteredpropertycache` to get called on every
access. In that case the new code makes a standard attribute access to the
property. If a value is cached it will be used.

The `propertycache` test file have been augmented with test about this issue.

import os, sys, time
from mercurial import hg, ui, commands, 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 = ui.ui()
# hide outer repo
hg.peer(u, {}, '.', create=True)

# clone with symlink support
hg.clone(u, {}, BUNDLEPATH, 'test0')

repo = hg.repository(u, 'test0')

# 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

# dereference links as if a Samba server has exported this to a
# Windows client
for f in 'test0/a.lnk', 'test0/d/b.lnk':
    os.unlink(f)
    fp = open(f, 'wb')
    fp.write(util.readfile(f[:-4]))
    fp.close()

# reload repository
u = ui.ui()
repo = hg.repository(u, 'test0')
commands.status(u, repo)

# try cloning a repo which contains symlinks
u = ui.ui()
hg.clone(u, {}, BUNDLEPATH, 'test1')