@@ -214,6 +214,9 @@ def diff(self, other=None, paths=None, create_patch=False, **kwargs):
 		Note
 			Rename detection will only work if create_patch is True
 		"""
+		# import it in a retared fashion to avoid dependency cycle
+		from git.diff import Diff
+		
 		args = list(self._diff_args[:])
 		args.append( "--abbrev=40" )		# we need full shas
 		args.append( "--full-index" )		# get full index paths, not only filenames
@@ -237,9 +240,9 @@ def diff(self, other=None, paths=None, create_patch=False, **kwargs):
 		kwargs['as_process'] = True
 		proc = self.repo.git.diff(*args, **kwargs)
 
-		diff_method = diff.Diff._index_from_raw_format
+		diff_method = Diff._index_from_raw_format
 		if create_patch:
-			diff_method = diff.Diff._index_from_patch_format(self.repo, proc.stdout)
+			diff_method = Diff._index_from_patch_format
 		return diff_method(self.repo, proc.stdout)
 
 
@@ -28,5 +28,35 @@ def test_diff_with_rename(self):
 		assert_equal(diff.rename_from, 'AUTHORS')
 		assert_equal(diff.rename_to, 'CONTRIBUTORS')
 
+	def test_diff_patch_format(self):
+		# test all of the 'old' format diffs for completness - it should at least
+		# be able to deal with it
+		fixtures = ("diff_2", "diff_2f", "diff_f", "diff_i", "diff_mode_only", 
+					"diff_new_mode", "diff_numstat", "diff_p", "diff_rename", 
+					"diff_tree_numstat_root" )
+		
+		for fixture_name in fixtures:
+			diff_proc = ListProcessAdapter(fixture(fixture_name))
+			diffs = Diff._index_from_patch_format(self.repo, diff_proc.stdout)
+		# END for each fixture
+
 	def test_diff_interface(self):
+		# test a few variations of the main diff routine
+		for i, commit in enumerate(self.repo.iter_commits('0.1.6', max_count=10)):
+			diff_item = commit
+			if i%2 == 0:
+				diff_item = commit.tree
+			# END use tree every second item
+			
+			for other in (None, commit.parents[0]):
+				for paths in (None, "CHANGES", ("CHANGES", "lib")):
+					for create_patch in range(2):
+						diff_index = diff_item.diff(other, paths, create_patch)
+						assert diff_index
+					# END for each patch option
+				# END for each path option
+			# END for each other side
+		# END for each commit
+		
+		
 		self.fail( "TODO: Test full diff interface on commits, trees, index, patch and non-patch" )