Don't let ResolveError leak out from local_attr, when using .mro().

2 files changed, 13 insertions, 1 deletions

diff --git a/astroid/scoped_nodes.py b/astroid/scoped_nodes.py
index 510961e..4fbcaea 100644
--- a/astroid/scoped_nodes.py
+++ b/astroid/scoped_nodes.py
@@ -1143,7 +1143,12 @@ class Class(Statement, LocalsDictNodeNG, FilterStmtsMixin):
         if self.newstyle and all(n.newstyle for n in self.ancestors(context)):
             # Look up in the mro if we can. This will result in the
             # attribute being looked up just as Python does it.
-            ancestors = self.mro(context)[1:]
+            try:
+                ancestors = self.mro(context)[1:]
+            except ResolveError:
+                # Reraise it as NotFoundError, there's no reason
+                # for ResolveError to leak out.
+                six.raise_from(NotFoundError, ResolveError)
         else:
             ancestors = self.ancestors(context)
         for astroid in ancestors:
diff --git a/astroid/tests/unittest_scoped_nodes.py b/astroid/tests/unittest_scoped_nodes.py
index 13af40c..db409cf 100644
--- a/astroid/tests/unittest_scoped_nodes.py
+++ b/astroid/tests/unittest_scoped_nodes.py
@@ -1319,6 +1319,13 @@ class ClassNodeTest(ModuleLoader, unittest.TestCase):
         """)
         self.assertIsNone(cls.implicit_metaclass())
 
+    def test_local_attr_invalid_mro(self):
+        cls = test_utils.extract_node("""
+        class A(object, object):
+            pass
+        """)
+        self.assertRaises(NotFoundError, cls.local_attr, 'test')
+
 
 if __name__ == '__main__':
     unittest.main()