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

phases: invalidate the phases set less often on retract boundary

We already have the information to update the phase set, so we do so directly
instead of invalidating the cache.

This show a sizeable speedup in our `perf::unbundle` benchmark on the
many-draft mozilla-try repository.

### data-env-vars.name            = mozilla-try-2023-03-22-zstd-sparse-revlog
  # benchmark.name                = hg.perf.perf-unbundle
  # bin-env-vars.hg.flavor        = no-rust
  # bin-env-vars.hg.py-re2-module = default
  # benchmark.variants.issue6528  = disabled

  # benchmark.variants.revs = last-10
before: 2.055259 seconds
after:  1.887064 seconds (-8.18%)
  # benchmark.variants.revs = last-100
before: 2.409239 seconds
after:  2.222429 seconds (-7.75%)
  # benchmark.variants.revs = last-1000
before: 3.945648 seconds
after:  3.762480 seconds (-4.64%)

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)