Catch an error with illegal class instances, fixes #1491

2020-02-03 22:27:48 +01:00
parent a49c757b8a
commit 3388a9659b
2 changed files with 13 additions and 1 deletions
@@ -570,4 +570,6 @@ def _is_class_instance(obj):
    except AttributeError:
        return False
    else:
-        return cls != type and not issubclass(cls, NOT_CLASS_TYPES)
+        # The isinstance check for cls is just there so issubclass doesn't
+        # raise an exception.
+        return cls != type and isinstance(cls, type) and not issubclass(cls, NOT_CLASS_TYPES)