Check that generic is not a ForwardRef before accessing its attrs

Author: dr-carlos

Lib/test/test_annotationlib.py

@@ -1677,18 +1677,21 @@ def test_name_lookup_without_eval(self):
 
     def test_evaluate_undefined_generic(self):
         # Test the codepath where have to eval() with undefined variables.
-        fwdref = ForwardRef("glob[int, undef]").evaluate(format=Format.FORWARDREF, globals={"glob": dict})
-        self.assertIs(fwdref.__origin__, dict)
-        self.assertIs(fwdref.__args__[0], int)
+        generic = ForwardRef("glob[int, undef]").evaluate(format=Format.FORWARDREF, globals={"glob": dict})
+        self.assertNotIsInstance(generic, ForwardRef)
+        self.assertIs(generic.__origin__, dict)
+        self.assertIs(generic.__args__[0], int)
 
-        fwdref = ForwardRef("loc[int, undef]").evaluate(format=Format.FORWARDREF, locals={"loc": dict})
-        self.assertIs(fwdref.__origin__, dict)
-        self.assertIs(fwdref.__args__[0], int)
+        generic = ForwardRef("loc[int, undef]").evaluate(format=Format.FORWARDREF, locals={"loc": dict})
+        self.assertNotIsInstance(generic, ForwardRef)
+        self.assertIs(generic.__origin__, dict)
+        self.assertIs(generic.__args__[0], int)
 
         # Ensure that globals overwrite builtins
-        fwdref = ForwardRef("list[int, undef]").evaluate(format=Format.FORWARDREF, globals={"list": dict})
-        self.assertIs(fwdref.__origin__, dict)
-        self.assertIs(fwdref.__args__[0], int)
+        generic = ForwardRef("list[int, undef]").evaluate(format=Format.FORWARDREF, globals={"list": dict})
+        self.assertNotIsInstance(generic, ForwardRef)
+        self.assertIs(generic.__origin__, dict)
+        self.assertIs(generic.__args__[0], int)
 
     def test_fwdref_invalid_syntax(self):
         fr = ForwardRef("if")