view contrib/lock-checker.py @ 23381:cc0ff93d0c0c stable

changegroup: fix file linkrevs during reorders (issue4462)

Previously, if reorder was true during the creation of a changegroup bundle,
it was possible that the manifest and filelogs would be reordered such that the
resulting bundle filelog had a linkrev that pointed to a commit that was not
the earliest instance of the filelog revision. For example:

With commits:

0<-1<---3<-4
  \       /
   --2<---

if 2 and 3 added the same version of a file, if the manifests of 2 and 3 have
their order reversed, but the changelog did not, it could produce a filelog with
linkrevs 0<-3 instead of 0<-2, which meant if commit 3 was stripped, it would
delete that file data from the repository and commit 2 would be corrupt (as
would any future pulls that tried to build upon that version of the file).

The fix is to make the linkrev fixup smarter. Previously it considered the first
manifest that added a file to be the first commit that added that file, which is
not true. Now, for every file revision we add to the bundle we make sure we
attach it to the earliest applicable linkrev.

"""Extension to verify locks are obtained in the required places.

This works by wrapping functions that should be surrounded by a lock
and asserting the lock is held. Missing locks are called out with a
traceback printed to stderr.

This currently only checks store locks, not working copy locks.
"""
import os
from mercurial import util

def _checklock(repo):
    l = repo._lockref and repo._lockref()
    if l is None or not l.held:
        util.debugstacktrace('missing lock', skip=1)

def reposetup(ui, repo):
    orig = repo.__class__
    class lockcheckrepo(repo.__class__):
        def _writejournal(self, *args, **kwargs):
            _checklock(self)
            return orig._writejournal(self, *args, **kwargs)

        def transaction(self, *args, **kwargs):
            _checklock(self)
            return orig.transaction(self, *args, **kwargs)

        # TODO(durin42): kiilerix had a commented-out lock check in
        # _writebranchcache and _writerequirements

        def _tag(self, *args, **kwargs):
            _checklock(self)
            return orig._tag(self, *args, **kwargs)

        def write(self, *args, **kwargs):
            assert os.path.lexists(self._join('.hg/wlock'))
            return orig.write(self, *args, **kwargs)

    repo.__class__ = lockcheckrepo