Handle non-unicode __name__, drop unnecessary cast

Author: johnslavik

Lib/test/test_exceptions.py

@@ -2162,6 +2162,15 @@ def raise_custom(name):
         self.assertIs(cm.exception.obj, nameless_mod)
         self.assertEqual(cm.exception.name, "missing4")
 
+        nameless_mod = ModuleType("broken")
+        nameless_mod.__dict__["__name__"] = 10j
+        nameless_mod.__getattr__ = raise_with_name
+        with self.assertRaises(AttributeError) as cm:
+            getattr(nameless_mod, "missing4")
+        self.assertEqual(str(cm.exception), "module has no attribute 'missing4'")
+        self.assertIs(cm.exception.obj, nameless_mod)
+        self.assertEqual(cm.exception.name, "missing4")
+
     # Note: name suggestion tests live in `test_traceback`.
 
 

Objects/exceptions.c

@@ -2741,16 +2741,17 @@ AttributeError_str(PyObject *op)
         if (PyDict_GetItemRef(mod->md_dict, &_Py_ID(__name__), &modname) < 0) {
             goto error;
         }
-        if (modname) {
+        if (modname && PyUnicode_Check(modname)) {
             result = PyUnicode_FromFormat("module '%U' has no attribute '%U'",
                                           modname, name);
             Py_DECREF(modname);
         } else {
+            Py_XDECREF(modname);
             result = PyUnicode_FromFormat("module has no attribute '%U'", name);
         }
     } else if (PyType_Check(obj)) {
         result = PyUnicode_FromFormat("type object '%N' has no attribute '%U'",
-                                      _PyType_CAST(obj), name);
+                                      obj, name);
     } else {
         result = PyUnicode_FromFormat("'%T' object has no attribute '%U'",
                                       obj, name);