convert: fix the RevisionSpec import in the bzr module

This import was failing (because its invalid) which was resulting in
the following tests failing with chg running:

 - test-convert-bzr.t
 - test-convert-bzr-directories.t
 - test-convert-bzr-ghosts.t
 - test-convert-bzr-treeroot.t
 - test-convert-bzr-114.t
 - test-convert-bzr-merges.t

This commit fixes the import which in turn fixes the tests.

Test Plan:
Ran the aforementioned tests with and without '--chg' option.

Differential Revision: https://phab.mercurial-scm.org/D936

hgext/convert/bzr.py

@@ -1,297 +1,298 b''
 # bzr.py - bzr support for the convert extension
 #
 #  Copyright 2008, 2009 Marek Kubica <[e-mail]> and others
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 # This module is for handling 'bzr', that was formerly known as Bazaar-NG;
 # it cannot access 'bar' repositories, but they were never used very much
 from __future__ import absolute_import
 
 import os
 
 from mercurial.i18n import _
 from mercurial import (
     demandimport,
     error
 )
 from . import common
 
 # these do not work with demandimport, blacklist
 demandimport.ignore.extend([
         'bzrlib.transactions',
         'bzrlib.urlutils',
         'ElementPath',
     ])
 
 try:
     # bazaar imports
     import bzrlib.bzrdir
     import bzrlib.errors
     import bzrlib.revision
-    import bzrlib.revisionspec.RevisionSpec
+    import bzrlib.revisionspec
     bzrdir = bzrlib.bzrdir
     errors = bzrlib.errors
     revision = bzrlib.revision
     revisionspec = bzrlib.revisionspec
+    revisionspec.RevisionSpec
 except ImportError:
     pass
 
 supportedkinds = ('file', 'symlink')
 
 class bzr_source(common.converter_source):
     """Reads Bazaar repositories by using the Bazaar Python libraries"""
 
     def __init__(self, ui, path, revs=None):
         super(bzr_source, self).__init__(ui, path, revs=revs)
 
         if not os.path.exists(os.path.join(path, '.bzr')):
             raise common.NoRepo(_('%s does not look like a Bazaar repository')
                               % path)
 
         try:
             # access bzrlib stuff
             bzrdir
         except NameError:
             raise common.NoRepo(_('Bazaar modules could not be loaded'))
 
         path = os.path.abspath(path)
         self._checkrepotype(path)
         try:
             self.sourcerepo = bzrdir.BzrDir.open(path).open_repository()
         except errors.NoRepositoryPresent:
             raise common.NoRepo(_('%s does not look like a Bazaar repository')
                               % path)
         self._parentids = {}
 
     def _checkrepotype(self, path):
         # Lightweight checkouts detection is informational but probably
         # fragile at API level. It should not terminate the conversion.
         try:
             dir = bzrdir.BzrDir.open_containing(path)[0]
             try:
                 tree = dir.open_workingtree(recommend_upgrade=False)
                 branch = tree.branch
             except (errors.NoWorkingTree, errors.NotLocalUrl):
                 tree = None
                 branch = dir.open_branch()
             if (tree is not None and tree.bzrdir.root_transport.base !=
                 branch.bzrdir.root_transport.base):
                 self.ui.warn(_('warning: lightweight checkouts may cause '
                                'conversion failures, try with a regular '
                                'branch instead.\n'))
         except Exception:
             self.ui.note(_('bzr source type could not be determined\n'))
 
     def before(self):
         """Before the conversion begins, acquire a read lock
         for all the operations that might need it. Fortunately
         read locks don't block other reads or writes to the
         repository, so this shouldn't have any impact on the usage of
         the source repository.
 
         The alternative would be locking on every operation that
         needs locks (there are currently two: getting the file and
         getting the parent map) and releasing immediately after,
         but this approach can take even 40% longer."""
         self.sourcerepo.lock_read()
 
     def after(self):
         self.sourcerepo.unlock()
 
     def _bzrbranches(self):
         return self.sourcerepo.find_branches(using=True)
 
     def getheads(self):
         if not self.revs:
             # Set using=True to avoid nested repositories (see issue3254)
             heads = sorted([b.last_revision() for b in self._bzrbranches()])
         else:
             revid = None
             for branch in self._bzrbranches():
                 try:
                     r = revisionspec.RevisionSpec.from_string(self.revs[0])
                     info = r.in_history(branch)
                 except errors.BzrError:
                     pass
                 revid = info.rev_id
             if revid is None:
                 raise error.Abort(_('%s is not a valid revision')
                                   % self.revs[0])
             heads = [revid]
         # Empty repositories return 'null:', which cannot be retrieved
         heads = [h for h in heads if h != 'null:']
         return heads
 
     def getfile(self, name, rev):
         revtree = self.sourcerepo.revision_tree(rev)
         fileid = revtree.path2id(name.decode(self.encoding or 'utf-8'))
         kind = None
         if fileid is not None:
             kind = revtree.kind(fileid)
         if kind not in supportedkinds:
             # the file is not available anymore - was deleted
             return None, None
         mode = self._modecache[(name, rev)]
         if kind == 'symlink':
             target = revtree.get_symlink_target(fileid)
             if target is None:
                 raise error.Abort(_('%s.%s symlink has no target')
                                  % (name, rev))
             return target, mode
         else:
             sio = revtree.get_file(fileid)
             return sio.read(), mode
 
     def getchanges(self, version, full):
         if full:
             raise error.Abort(_("convert from cvs does not support --full"))
         self._modecache = {}
         self._revtree = self.sourcerepo.revision_tree(version)
         # get the parentids from the cache
         parentids = self._parentids.pop(version)
         # only diff against first parent id
         prevtree = self.sourcerepo.revision_tree(parentids[0])
         files, changes = self._gettreechanges(self._revtree, prevtree)
         return files, changes, set()
 
     def getcommit(self, version):
         rev = self.sourcerepo.get_revision(version)
         # populate parent id cache
         if not rev.parent_ids:
             parents = []
             self._parentids[version] = (revision.NULL_REVISION,)
         else:
             parents = self._filterghosts(rev.parent_ids)
             self._parentids[version] = parents
 
         branch = self.recode(rev.properties.get('branch-nick', u'default'))
         if branch == 'trunk':
             branch = 'default'
         return common.commit(parents=parents,
                 date='%d %d' % (rev.timestamp, -rev.timezone),
                 author=self.recode(rev.committer),
                 desc=self.recode(rev.message),
                 branch=branch,
                 rev=version)
 
     def gettags(self):
         bytetags = {}
         for branch in self._bzrbranches():
             if not branch.supports_tags():
                 return {}
             tagdict = branch.tags.get_tag_dict()
             for name, rev in tagdict.iteritems():
                 bytetags[self.recode(name)] = rev
         return bytetags
 
     def getchangedfiles(self, rev, i):
         self._modecache = {}
         curtree = self.sourcerepo.revision_tree(rev)
         if i is not None:
             parentid = self._parentids[rev][i]
         else:
             # no parent id, get the empty revision
             parentid = revision.NULL_REVISION
 
         prevtree = self.sourcerepo.revision_tree(parentid)
         changes = [e[0] for e in self._gettreechanges(curtree, prevtree)[0]]
         return changes
 
     def _gettreechanges(self, current, origin):
         revid = current._revision_id
         changes = []
         renames = {}
         seen = set()
         # Process the entries by reverse lexicographic name order to
         # handle nested renames correctly, most specific first.
         curchanges = sorted(current.iter_changes(origin),
                             key=lambda c: c[1][0] or c[1][1],
                             reverse=True)
         for (fileid, paths, changed_content, versioned, parent, name,
             kind, executable) in curchanges:
 
             if paths[0] == u'' or paths[1] == u'':
                 # ignore changes to tree root
                 continue
 
             # bazaar tracks directories, mercurial does not, so
             # we have to rename the directory contents
             if kind[1] == 'directory':
                 if kind[0] not in (None, 'directory'):
                     # Replacing 'something' with a directory, record it
                     # so it can be removed.
                     changes.append((self.recode(paths[0]), revid))
 
                 if kind[0] == 'directory' and None not in paths:
                     renaming = paths[0] != paths[1]
                     # neither an add nor an delete - a move
                     # rename all directory contents manually
                     subdir = origin.root_inventory.path2id(paths[0])
                     # get all child-entries of the directory
                     for name, entry in origin.root_inventory.iter_entries(
                             subdir):
                         # hg does not track directory renames
                         if entry.kind == 'directory':
                             continue
                         frompath = self.recode(paths[0] + '/' + name)
                         if frompath in seen:
                             # Already handled by a more specific change entry
                             # This is important when you have:
                             # a => b
                             # a/c => a/c
                             # Here a/c must not be renamed into b/c
                             continue
                         seen.add(frompath)
                         if not renaming:
                             continue
                         topath = self.recode(paths[1] + '/' + name)
                         # register the files as changed
                         changes.append((frompath, revid))
                         changes.append((topath, revid))
                         # add to mode cache
                         mode = ((entry.executable and 'x')
                                 or (entry.kind == 'symlink' and 's')
                                 or '')
                         self._modecache[(topath, revid)] = mode
                         # register the change as move
                         renames[topath] = frompath
 
                 # no further changes, go to the next change
                 continue
 
             # we got unicode paths, need to convert them
             path, topath = paths
             if path is not None:
                 path = self.recode(path)
             if topath is not None:
                 topath = self.recode(topath)
             seen.add(path or topath)
 
             if topath is None:
                 # file deleted
                 changes.append((path, revid))
                 continue
 
             # renamed
             if path and path != topath:
                 renames[topath] = path
                 changes.append((path, revid))
 
             # populate the mode cache
             kind, executable = [e[1] for e in (kind, executable)]
             mode = ((executable and 'x') or (kind == 'symlink' and 'l')
                     or '')
             self._modecache[(topath, revid)] = mode
             changes.append((topath, revid))
 
         return changes, renames
 
     def _filterghosts(self, ids):
         """Filters out ghost revisions which hg does not support, see
         <http://bazaar-vcs.org/GhostRevision>
         """
         parentmap = self.sourcerepo.get_parent_map(ids)
         parents = tuple([parent for parent in ids if parent in parentmap])
         return parents