vcs: Fix internal server error when trying to get diff from Mercurial for paths that include globbing patterns (Issue #308):

- Treat passed-in paths as exact matches, dissallowing any type of
  globbing/regex/pattern matching.
- Added accompanying tests.

kallithea/lib/vcs/backends/hg/repository.py

@@ -1,627 +1,627 b''
 # -*- coding: utf-8 -*-
 """
     vcs.backends.hg.repository
     ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
     Mercurial repository implementation.
 
     :created_on: Apr 8, 2010
     :copyright: (c) 2010-2011 by Marcin Kuzminski, Lukasz Balcerzak.
 """
 
 import os
 import time
 import urllib
 import urllib2
 import logging
 import datetime
 
 from kallithea.lib.vcs.backends.base import BaseRepository, CollectionGenerator
 
 from kallithea.lib.vcs.exceptions import (
     BranchDoesNotExistError, ChangesetDoesNotExistError, EmptyRepositoryError,
     RepositoryError, VCSError, TagAlreadyExistError, TagDoesNotExistError
 )
 from kallithea.lib.vcs.utils import (
     author_email, author_name, date_fromtimestamp, makedate, safe_unicode, safe_str,
 )
 from kallithea.lib.vcs.utils.lazy import LazyProperty
 from kallithea.lib.vcs.utils.ordered_dict import OrderedDict
 from kallithea.lib.vcs.utils.paths import abspath
 from kallithea.lib.vcs.utils.hgcompat import (
     ui, nullid, match, patch, diffopts, clone, get_contact,
     localrepository, RepoLookupError, Abort, RepoError, hex, scmutil, hg_url,
     httpbasicauthhandler, httpdigestauthhandler, peer, httppeer, sshpeer
 )
 
 from .changeset import MercurialChangeset
 from .inmemory import MercurialInMemoryChangeset
 from .workdir import MercurialWorkdir
 
 log = logging.getLogger(__name__)
 
 
 class MercurialRepository(BaseRepository):
     """
     Mercurial repository backend
     """
     DEFAULT_BRANCH_NAME = 'default'
     scm = 'hg'
 
     def __init__(self, repo_path, create=False, baseui=None, src_url=None,
                  update_after_clone=False):
         """
         Raises RepositoryError if repository could not be find at the given
         ``repo_path``.
 
         :param repo_path: local path of the repository
         :param create=False: if set to True, would try to create repository if
            it does not exist rather than raising exception
         :param baseui=None: user data
         :param src_url=None: would try to clone repository from given location
         :param update_after_clone=False: sets update of working copy after
           making a clone
         """
 
         if not isinstance(repo_path, str):
             raise VCSError('Mercurial backend requires repository path to '
                            'be instance of <str> got %s instead' %
                            type(repo_path))
 
         self.path = abspath(repo_path)
         self.baseui = baseui or ui.ui()
         # We've set path and ui, now we can set _repo itself
         self._repo = self._get_repo(create, src_url, update_after_clone)
 
     @property
     def _empty(self):
         """
         Checks if repository is empty ie. without any changesets
         """
         # TODO: Following raises errors when using InMemoryChangeset...
         # return len(self._repo.changelog) == 0
         return len(self.revisions) == 0
 
     @LazyProperty
     def revisions(self):
         """
         Returns list of revisions' ids, in ascending order.  Being lazy
         attribute allows external tools to inject shas from cache.
         """
         return self._get_all_revisions()
 
     @LazyProperty
     def name(self):
         return os.path.basename(self.path)
 
     @LazyProperty
     def branches(self):
         return self._get_branches()
 
     @LazyProperty
     def closed_branches(self):
         return self._get_branches(normal=False, closed=True)
 
     @LazyProperty
     def allbranches(self):
         """
         List all branches, including closed branches.
         """
         return self._get_branches(closed=True)
 
     def _get_branches(self, normal=True, closed=False):
         """
         Gets branches for this repository
         Returns only not closed branches by default
 
         :param closed: return also closed branches for mercurial
         :param normal: return also normal branches
         """
 
         if self._empty:
             return {}
 
         bt = OrderedDict()
         for bn, _heads, tip, isclosed in sorted(self._repo.branchmap().iterbranches()):
             if isclosed:
                 if closed:
                     bt[safe_unicode(bn)] = hex(tip)
             else:
                 if normal:
                     bt[safe_unicode(bn)] = hex(tip)
 
         return bt
 
     @LazyProperty
     def tags(self):
         """
         Gets tags for this repository
         """
         return self._get_tags()
 
     def _get_tags(self):
         if self._empty:
             return {}
 
         sortkey = lambda ctx: ctx[0]  # sort by name
         _tags = [(safe_unicode(n), hex(h),) for n, h in
                  self._repo.tags().items()]
 
         return OrderedDict(sorted(_tags, key=sortkey, reverse=True))
 
     def tag(self, name, user, revision=None, message=None, date=None,
             **kwargs):
         """
         Creates and returns a tag for the given ``revision``.
 
         :param name: name for new tag
         :param user: full username, i.e.: "Joe Doe <[e-mail]>"
         :param revision: changeset id for which new tag would be created
         :param message: message of the tag's commit
         :param date: date of tag's commit
 
         :raises TagAlreadyExistError: if tag with same name already exists
         """
         if name in self.tags:
             raise TagAlreadyExistError("Tag %s already exists" % name)
         changeset = self.get_changeset(revision)
         local = kwargs.setdefault('local', False)
 
         if message is None:
             message = "Added tag %s for changeset %s" % (name,
                 changeset.short_id)
 
         if date is None:
             date = datetime.datetime.now().ctime()
 
         try:
             self._repo.tag(name, changeset._ctx.node(), message, local, user,
                 date)
         except Abort as e:
             raise RepositoryError(e.message)
 
         # Reinitialize tags
         self.tags = self._get_tags()
         tag_id = self.tags[name]
 
         return self.get_changeset(revision=tag_id)
 
     def remove_tag(self, name, user, message=None, date=None):
         """
         Removes tag with the given ``name``.
 
         :param name: name of the tag to be removed
         :param user: full username, i.e.: "Joe Doe <[e-mail]>"
         :param message: message of the tag's removal commit
         :param date: date of tag's removal commit
 
         :raises TagDoesNotExistError: if tag with given name does not exists
         """
         if name not in self.tags:
             raise TagDoesNotExistError("Tag %s does not exist" % name)
         if message is None:
             message = "Removed tag %s" % name
         if date is None:
             date = datetime.datetime.now().ctime()
         local = False
 
         try:
             self._repo.tag(name, nullid, message, local, user, date)
             self.tags = self._get_tags()
         except Abort as e:
             raise RepositoryError(e.message)
 
     @LazyProperty
     def bookmarks(self):
         """
         Gets bookmarks for this repository
         """
         return self._get_bookmarks()
 
     def _get_bookmarks(self):
         if self._empty:
             return {}
 
         sortkey = lambda ctx: ctx[0]  # sort by name
         _bookmarks = [(safe_unicode(n), hex(h),) for n, h in
                  self._repo._bookmarks.items()]
         return OrderedDict(sorted(_bookmarks, key=sortkey, reverse=True))
 
     def _get_all_revisions(self):
 
         return [self._repo[x].hex() for x in self._repo.filtered('visible').changelog.revs()]
 
     def get_diff(self, rev1, rev2, path='', ignore_whitespace=False,
                   context=3):
         """
         Returns (git like) *diff*, as plain text. Shows changes introduced by
         ``rev2`` since ``rev1``.
 
         :param rev1: Entry point from which diff is shown. Can be
           ``self.EMPTY_CHANGESET`` - in this case, patch showing all
           the changes since empty state of the repository until ``rev2``
         :param rev2: Until which revision changes should be shown.
         :param ignore_whitespace: If set to ``True``, would not show whitespace
           changes. Defaults to ``False``.
         :param context: How many lines before/after changed lines should be
           shown. Defaults to ``3``. If negative value is passed-in, it will be
           set to ``0`` instead.
         """
 
         # Negative context values make no sense, and will result in
         # errors. Ensure this does not happen.
         if context < 0:
             context = 0
 
         if hasattr(rev1, 'raw_id'):
             rev1 = getattr(rev1, 'raw_id')
 
         if hasattr(rev2, 'raw_id'):
             rev2 = getattr(rev2, 'raw_id')
 
         # Check if given revisions are present at repository (may raise
         # ChangesetDoesNotExistError)
         if rev1 != self.EMPTY_CHANGESET:
             self.get_changeset(rev1)
         self.get_changeset(rev2)
         if path:
-            file_filter = match(self.path, '', [path])
+            file_filter = match(self.path, '', [path], exact=True)
         else:
             file_filter = None
 
         return ''.join(patch.diff(self._repo, rev1, rev2, match=file_filter,
                           opts=diffopts(git=True,
                                         showfunc=True,
                                         ignorews=ignore_whitespace,
                                         context=context)))
 
     @classmethod
     def _check_url(cls, url, repoui=None):
         """
         Function will check given url and try to verify if it's a valid
         link. Sometimes it may happened that mercurial will issue basic
         auth request that can cause whole API to hang when used from python
         or other external calls.
 
         On failures it'll raise urllib2.HTTPError, exception is also thrown
         when the return code is non 200
         """
         # check first if it's not an local url
         if os.path.isdir(url) or url.startswith('file:'):
             return True
 
         if url.startswith('ssh:'):
             # in case of invalid uri or authentication issues, sshpeer will
             # throw an exception.
             sshpeer(repoui or ui.ui(), url).lookup('tip')
             return True
 
         url_prefix = None
         if '+' in url[:url.find('://')]:
             url_prefix, url = url.split('+', 1)
 
         handlers = []
         url_obj = hg_url(url)
         test_uri, authinfo = url_obj.authinfo()
         url_obj.passwd = '*****'
         cleaned_uri = str(url_obj)
 
         if authinfo:
             #create a password manager
             passmgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
             passmgr.add_password(*authinfo)
 
             handlers.extend((httpbasicauthhandler(passmgr),
                              httpdigestauthhandler(passmgr)))
 
         o = urllib2.build_opener(*handlers)
         o.addheaders = [('Content-Type', 'application/mercurial-0.1'),
                         ('Accept', 'application/mercurial-0.1')]
 
         q = {"cmd": 'between'}
         q.update({'pairs': "%s-%s" % ('0' * 40, '0' * 40)})
         qs = '?%s' % urllib.urlencode(q)
         cu = "%s%s" % (test_uri, qs)
         req = urllib2.Request(cu, None, {})
 
         try:
             resp = o.open(req)
             if resp.code != 200:
                 raise Exception('Return Code is not 200')
         except Exception as e:
             # means it cannot be cloned
             raise urllib2.URLError("[%s] org_exc: %s" % (cleaned_uri, e))
 
         if not url_prefix: # skip svn+http://... (and git+... too)
             # now check if it's a proper hg repo
             try:
                 httppeer(repoui or ui.ui(), url).lookup('tip')
             except Exception as e:
                 raise urllib2.URLError(
                     "url [%s] does not look like an hg repo org_exc: %s"
                     % (cleaned_uri, e))
 
         return True
 
     def _get_repo(self, create, src_url=None, update_after_clone=False):
         """
         Function will check for mercurial repository in given path and return
         a localrepo object. If there is no repository in that path it will
         raise an exception unless ``create`` parameter is set to True - in
         that case repository would be created and returned.
         If ``src_url`` is given, would try to clone repository from the
         location at given clone_point. Additionally it'll make update to
         working copy accordingly to ``update_after_clone`` flag
         """
 
         try:
             if src_url:
                 url = str(self._get_url(src_url))
                 opts = {}
                 if not update_after_clone:
                     opts.update({'noupdate': True})
                 MercurialRepository._check_url(url, self.baseui)
                 clone(self.baseui, url, self.path, **opts)
 
                 # Don't try to create if we've already cloned repo
                 create = False
             return localrepository(self.baseui, self.path, create=create)
         except (Abort, RepoError) as err:
             if create:
                 msg = "Cannot create repository at %s. Original error was %s"\
                     % (self.path, err)
             else:
                 msg = "Not valid repository at %s. Original error was %s"\
                     % (self.path, err)
             raise RepositoryError(msg)
 
     @LazyProperty
     def in_memory_changeset(self):
         return MercurialInMemoryChangeset(self)
 
     @LazyProperty
     def description(self):
         undefined_description = u'unknown'
         _desc = self._repo.ui.config('web', 'description', None, untrusted=True)
         return safe_unicode(_desc or undefined_description)
 
     @LazyProperty
     def contact(self):
         undefined_contact = u'Unknown'
         return safe_unicode(get_contact(self._repo.ui.config)
                             or undefined_contact)
 
     @LazyProperty
     def last_change(self):
         """
         Returns last change made on this repository as datetime object
         """
         return date_fromtimestamp(self._get_mtime(), makedate()[1])
 
     def _get_mtime(self):
         try:
             return time.mktime(self.get_changeset().date.timetuple())
         except RepositoryError:
             #fallback to filesystem
             cl_path = os.path.join(self.path, '.hg', "00changelog.i")
             st_path = os.path.join(self.path, '.hg', "store")
             if os.path.exists(cl_path):
                 return os.stat(cl_path).st_mtime
             else:
                 return os.stat(st_path).st_mtime
 
     def _get_revision(self, revision):
         """
         Gets an ID revision given as str. This will always return a fill
         40 char revision number
 
         :param revision: str or int or None
         """
         if isinstance(revision, unicode):
             revision = safe_str(revision)
 
         if self._empty:
             raise EmptyRepositoryError("There are no changesets yet")
 
         if revision in [-1, 'tip', None]:
             revision = 'tip'
 
         try:
             revision = hex(self._repo.lookup(revision))
         except (LookupError, ):
             msg = ("Ambiguous identifier `%s` for %s" % (revision, self))
             raise ChangesetDoesNotExistError(msg)
         except (IndexError, ValueError, RepoLookupError, TypeError):
             msg = ("Revision %s does not exist for %s" % (revision, self))
             raise ChangesetDoesNotExistError(msg)
 
         return revision
 
     def get_ref_revision(self, ref_type, ref_name):
         """
         Returns revision number for the given reference.
         """
         ref_name = safe_str(ref_name)
         if ref_type == 'rev' and not ref_name.strip('0'):
             return self.EMPTY_CHANGESET
         # lookup up the exact node id
         _revset_predicates = {
                 'branch': 'branch',
                 'book': 'bookmark',
                 'tag': 'tag',
                 'rev': 'id',
             }
         # avoid expensive branch(x) iteration over whole repo
         rev_spec = "%%s & %s(%%s)" % _revset_predicates[ref_type]
         try:
             revs = self._repo.revs(rev_spec, ref_name, ref_name)
         except LookupError:
             msg = ("Ambiguous identifier %s:%s for %s" % (ref_type, ref_name, self.name))
             raise ChangesetDoesNotExistError(msg)
         except RepoLookupError:
             msg = ("Revision %s:%s does not exist for %s" % (ref_type, ref_name, self.name))
             raise ChangesetDoesNotExistError(msg)
         if revs:
             try:
                 revision = revs.last()
             except AttributeError:
                 # removed in hg 3.2
                 revision = revs[-1]
         else:
             # TODO: just report 'not found'?
             revision = ref_name
 
         return self._get_revision(revision)
 
     def _get_archives(self, archive_name='tip'):
         allowed = self.baseui.configlist("web", "allow_archive",
                                          untrusted=True)
         for i in [('zip', '.zip'), ('gz', '.tar.gz'), ('bz2', '.tar.bz2')]:
             if i[0] in allowed or self._repo.ui.configbool("web",
                                                            "allow" + i[0],
                                                            untrusted=True):
                 yield {"type": i[0], "extension": i[1], "node": archive_name}
 
     def _get_url(self, url):
         """
         Returns normalized url. If schema is not given, would fall
         to filesystem
         (``file:///``) schema.
         """
         url = str(url)
         if url != 'default' and not '://' in url:
             url = "file:" + urllib.pathname2url(url)
         return url
 
     def get_hook_location(self):
         """
         returns absolute path to location where hooks are stored
         """
         return os.path.join(self.path, '.hg', '.hgrc')
 
     def get_changeset(self, revision=None):
         """
         Returns ``MercurialChangeset`` object representing repository's
         changeset at the given ``revision``.
         """
         revision = self._get_revision(revision)
         changeset = MercurialChangeset(repository=self, revision=revision)
         return changeset
 
     def get_changesets(self, start=None, end=None, start_date=None,
                        end_date=None, branch_name=None, reverse=False):
         """
         Returns iterator of ``MercurialChangeset`` objects from start to end
         (both are inclusive)
 
         :param start: None, str, int or mercurial lookup format
         :param end:  None, str, int or mercurial lookup format
         :param start_date:
         :param end_date:
         :param branch_name:
         :param reversed: return changesets in reversed order
         """
 
         start_raw_id = self._get_revision(start)
         start_pos = self.revisions.index(start_raw_id) if start else None
         end_raw_id = self._get_revision(end)
         end_pos = self.revisions.index(end_raw_id) if end else None
 
         if None not in [start, end] and start_pos > end_pos:
             raise RepositoryError("Start revision '%s' cannot be "
                                   "after end revision '%s'" % (start, end))
 
         if branch_name and branch_name not in self.allbranches.keys():
             msg = ("Branch %s not found in %s" % (branch_name, self))
             raise BranchDoesNotExistError(msg)
         if end_pos is not None:
             end_pos += 1
         #filter branches
         filter_ = []
         if branch_name:
             filter_.append('branch("%s")' % (branch_name))
 
         if start_date and not end_date:
             filter_.append('date(">%s")' % start_date)
         if end_date and not start_date:
             filter_.append('date("<%s")' % end_date)
         if start_date and end_date:
             filter_.append('date(">%s") and date("<%s")' % (start_date, end_date))
         if filter_:
             revisions = scmutil.revrange(self._repo, filter_)
         else:
             revisions = self.revisions
 
         # this is very much a hack to turn this into a list; a better solution
         # would be to get rid of this function entirely and use revsets
         revs = list(revisions)[start_pos:end_pos]
         if reverse:
             revs = reversed(revs)
 
         return CollectionGenerator(self, revs)
 
     def pull(self, url):
         """
         Tries to pull changes from external location.
         """
         url = self._get_url(url)
         other = peer(self._repo, {}, url)
         try:
             # hg 3.2 moved push / pull to exchange module
             from mercurial import exchange
             exchange.pull(self._repo, other, heads=None, force=None)
         except ImportError:
             self._repo.pull(other, heads=None, force=None)
         except Abort as err:
             # Propagate error but with vcs's type
             raise RepositoryError(str(err))
 
     @LazyProperty
     def workdir(self):
         """
         Returns ``Workdir`` instance for this repository.
         """
         return MercurialWorkdir(self)
 
     def get_config_value(self, section, name=None, config_file=None):
         """
         Returns configuration value for a given [``section``] and ``name``.
 
         :param section: Section we want to retrieve value from
         :param name: Name of configuration we want to retrieve
         :param config_file: A path to file which should be used to retrieve
           configuration from (might also be a list of file paths)
         """
         if config_file is None:
             config_file = []
         elif isinstance(config_file, basestring):
             config_file = [config_file]
 
         config = self._repo.ui
         for path in config_file:
             config.readconfig(path)
         return config.config(section, name)
 
     def get_user_name(self, config_file=None):
         """
         Returns user's name from global configuration file.
 
         :param config_file: A path to file which should be used to retrieve
           configuration from (might also be a list of file paths)
         """
         username = self.get_config_value('ui', 'username')
         if username:
             return author_name(username)
         return None
 
     def get_user_email(self, config_file=None):
         """
         Returns user's email from global configuration file.
 
         :param config_file: A path to file which should be used to retrieve
           configuration from (might also be a list of file paths)
         """
         username = self.get_config_value('ui', 'username')
         if username:
             return author_email(username)
         return None

kallithea/tests/vcs/test_repository.py

@@ -1,228 +1,264 b''
 import datetime
 from kallithea.tests.vcs.base import _BackendTestMixin
 from kallithea.tests.vcs.conf import SCM_TESTS
 from kallithea.tests.vcs.conf import TEST_USER_CONFIG_FILE
 from kallithea.lib.vcs.nodes import FileNode
 from kallithea.lib.vcs.utils.compat import unittest
 from kallithea.lib.vcs.exceptions import ChangesetDoesNotExistError
 
 
 class RepositoryBaseTest(_BackendTestMixin):
     recreate_repo_per_test = False
 
     @classmethod
     def _get_commits(cls):
         return super(RepositoryBaseTest, cls)._get_commits()[:1]
 
     def test_get_config_value(self):
         self.assertEqual(self.repo.get_config_value('universal', 'foo',
             TEST_USER_CONFIG_FILE), 'bar')
 
     def test_get_config_value_defaults_to_None(self):
         self.assertEqual(self.repo.get_config_value('universal', 'nonexist',
             TEST_USER_CONFIG_FILE), None)
 
     def test_get_user_name(self):
         self.assertEqual(self.repo.get_user_name(TEST_USER_CONFIG_FILE),
             'Foo Bar')
 
     def test_get_user_email(self):
         self.assertEqual(self.repo.get_user_email(TEST_USER_CONFIG_FILE),
             '[e-mail]')
 
     def test_repo_equality(self):
         self.assertTrue(self.repo == self.repo)
 
     def test_repo_equality_broken_object(self):
         import copy
         _repo = copy.copy(self.repo)
         delattr(_repo, 'path')
         self.assertTrue(self.repo != _repo)
 
     def test_repo_equality_other_object(self):
         class dummy(object):
             path = self.repo.path
         self.assertTrue(self.repo != dummy())
 
 
 class RepositoryGetDiffTest(_BackendTestMixin):
 
     @classmethod
     def _get_commits(cls):
         commits = [
             {
                 'message': 'Initial commit',
                 'author': 'Joe Doe <[e-mail]>',
                 'date': datetime.datetime(2010, 1, 1, 20),
                 'added': [
                     FileNode('foobar', content='foobar'),
                     FileNode('foobar2', content='foobar2'),
                 ],
             },
             {
                 'message': 'Changed foobar, added foobar3',
                 'author': 'Jane Doe <[e-mail]>',
                 'date': datetime.datetime(2010, 1, 1, 21),
                 'added': [
                     FileNode('foobar3', content='foobar3'),
                 ],
                 'changed': [
                     FileNode('foobar', 'FOOBAR'),
                 ],
             },
             {
                 'message': 'Removed foobar, changed foobar3',
                 'author': 'Jane Doe <[e-mail]>',
                 'date': datetime.datetime(2010, 1, 1, 22),
                 'changed': [
                     FileNode('foobar3', content='FOOBAR\nFOOBAR\nFOOBAR\n'),
                 ],
                 'removed': [FileNode('foobar')],
             },
+            {
+                'message': u'Commit that contains glob pattern in filename',
+                'author': 'Jane Doe <[e-mail]>',
+                'date': datetime.datetime(2010, 1, 1, 22),
+                'added': [
+                    FileNode('README{', content='Strangely-named README file'),
+                ],
+            },
         ]
         return commits
 
     def test_raise_for_wrong(self):
         with self.assertRaises(ChangesetDoesNotExistError):
             self.repo.get_diff('a' * 40, 'b' * 40)
 
+    def test_glob_patterns_in_filename_do_not_raise_exception(self):
+        revs = self.repo.revisions
+
+        diff = self.repo.get_diff(revs[2], revs[3], path='README{') # should not raise
+
 
 class GitRepositoryGetDiffTest(RepositoryGetDiffTest, unittest.TestCase):
     backend_alias = 'git'
 
     def test_initial_commit_diff(self):
         initial_rev = self.repo.revisions[0]
         self.assertEqual(self.repo.get_diff(self.repo.EMPTY_CHANGESET, initial_rev), '''diff --git a/foobar b/foobar
 new file mode 100644
 index 0000000000000000000000000000000000000000..f6ea0495187600e7b2288c8ac19c5886383a4632
 --- /dev/null
 +++ b/foobar
 @@ -0,0 +1 @@
 +foobar
 \ No newline at end of file
 diff --git a/foobar2 b/foobar2
 new file mode 100644
 index 0000000000000000000000000000000000000000..e8c9d6b98e3dce993a464935e1a53f50b56a3783
 --- /dev/null
 +++ b/foobar2
 @@ -0,0 +1 @@
 +foobar2
 \ No newline at end of file
 ''')
 
     def test_second_changeset_diff(self):
         revs = self.repo.revisions
         self.assertEqual(self.repo.get_diff(revs[0], revs[1]), '''diff --git a/foobar b/foobar
 index f6ea0495187600e7b2288c8ac19c5886383a4632..389865bb681b358c9b102d79abd8d5f941e96551 100644
 --- a/foobar
 +++ b/foobar
 @@ -1 +1 @@
 -foobar
 \ No newline at end of file
 +FOOBAR
 \ No newline at end of file
 diff --git a/foobar3 b/foobar3
 new file mode 100644
 index 0000000000000000000000000000000000000000..c11c37d41d33fb47741cff93fa5f9d798c1535b0
 --- /dev/null
 +++ b/foobar3
 @@ -0,0 +1 @@
 +foobar3
 \ No newline at end of file
 ''')
 
     def test_third_changeset_diff(self):
         revs = self.repo.revisions
         self.assertEqual(self.repo.get_diff(revs[1], revs[2]), '''diff --git a/foobar b/foobar
 deleted file mode 100644
 index 389865bb681b358c9b102d79abd8d5f941e96551..0000000000000000000000000000000000000000
 --- a/foobar
 +++ /dev/null
 @@ -1 +0,0 @@
 -FOOBAR
 \ No newline at end of file
 diff --git a/foobar3 b/foobar3
 index c11c37d41d33fb47741cff93fa5f9d798c1535b0..f9324477362684ff692aaf5b9a81e01b9e9a671c 100644
 --- a/foobar3
 +++ b/foobar3
 @@ -1 +1,3 @@
 -foobar3
 \ No newline at end of file
 +FOOBAR
 +FOOBAR
 +FOOBAR
 ''')
 
+    def test_fourth_changeset_diff(self):
+        revs = self.repo.revisions
+        self.assertEqual(self.repo.get_diff(revs[2], revs[3]), '''diff --git a/README{ b/README{
+new file mode 100644
+index 0000000000000000000000000000000000000000..cdc0c1b5d234feedb37bbac19cd1b6442061102d
+--- /dev/null
++++ b/README{
+@@ -0,0 +1 @@
++Strangely-named README file
+\ No newline at end of file
+''')
+
 
 class HgRepositoryGetDiffTest(RepositoryGetDiffTest, unittest.TestCase):
     backend_alias = 'hg'
 
     def test_initial_commit_diff(self):
         initial_rev = self.repo.revisions[0]
         self.assertEqual(self.repo.get_diff(self.repo.EMPTY_CHANGESET, initial_rev), '''diff --git a/foobar b/foobar
 new file mode 100644
 --- /dev/null
 +++ b/foobar
 @@ -0,0 +1,1 @@
 +foobar
 \ No newline at end of file
 diff --git a/foobar2 b/foobar2
 new file mode 100644
 --- /dev/null
 +++ b/foobar2
 @@ -0,0 +1,1 @@
 +foobar2
 \ No newline at end of file
 ''')
 
     def test_second_changeset_diff(self):
         revs = self.repo.revisions
         self.assertEqual(self.repo.get_diff(revs[0], revs[1]), '''diff --git a/foobar b/foobar
 --- a/foobar
 +++ b/foobar
 @@ -1,1 +1,1 @@
 -foobar
 \ No newline at end of file
 +FOOBAR
 \ No newline at end of file
 diff --git a/foobar3 b/foobar3
 new file mode 100644
 --- /dev/null
 +++ b/foobar3
 @@ -0,0 +1,1 @@
 +foobar3
 \ No newline at end of file
 ''')
 
     def test_third_changeset_diff(self):
         revs = self.repo.revisions
         self.assertEqual(self.repo.get_diff(revs[1], revs[2]), '''diff --git a/foobar b/foobar
 deleted file mode 100644
 --- a/foobar
 +++ /dev/null
 @@ -1,1 +0,0 @@
 -FOOBAR
 \ No newline at end of file
 diff --git a/foobar3 b/foobar3
 --- a/foobar3
 +++ b/foobar3
 @@ -1,1 +1,3 @@
 -foobar3
 \ No newline at end of file
 +FOOBAR
 +FOOBAR
 +FOOBAR
 ''')
 
+    def test_fourth_changeset_diff(self):
+        revs = self.repo.revisions
+        self.assertEqual(self.repo.get_diff(revs[2], revs[3]), '''diff --git a/README{ b/README{
+new file mode 100644
+--- /dev/null
++++ b/README{
+@@ -0,0 +1,1 @@
++Strangely-named README file
+\ No newline at end of file
+''')
+
 
 # For each backend create test case class
 for alias in SCM_TESTS:
     attrs = {
         'backend_alias': alias,
     }
     cls_name = alias.capitalize() + RepositoryBaseTest.__name__
     bases = (RepositoryBaseTest, unittest.TestCase)
     globals()[cls_name] = type(cls_name, bases, attrs)
 
 if __name__ == '__main__':
     unittest.main()