bpo-34284: Null __new__ for curses.panel.panel

VadimPushtaev · VadimPushtaev · commit 96cefbf33ad0 · 2018-09-03T19:04:39.000+03:00
diff --git a/Lib/test/test_curses.py b/Lib/test/test_curses.py
@@ -14,6 +14,7 @@
 import sys
 import tempfile
 import unittest
+import re
 
 from test.support import requires, import_module, verbose, SaveSignals
 
@@ -306,6 +307,21 @@ def test_getmouse(self):
         curses.ungetmouse(0, 0, 0, 0, curses.BUTTON1_PRESSED)
         m = curses.getmouse()
 
+    @requires_curses_func('panel')
+    def test_panel_no_instantiation(self):
+        cant_create_message = re.escape("cannot create '_curses_panel.panel' instances")
+        object_message = re.escape(
+            'object.__new__(_curses_panel.panel) is not safe, '
+            'use _curses_panel.panel.__new__()'
+        )
+
+        with self.assertRaisesRegex(TypeError, cant_create_message):
+            curses.panel.panel()
+        with self.assertRaisesRegex(TypeError, cant_create_message):
+            curses.panel.panel.__new__(curses.panel.panel)
+        with self.assertRaisesRegex(TypeError, object_message):
+            object.__new__(curses.panel.panel)
+
     @requires_curses_func('panel')
     def test_userptr_without_set(self):
         w = curses.newwin(10, 10)
diff --git a/Modules/_curses_panel.c b/Modules/_curses_panel.c
@@ -477,6 +477,7 @@ static PyMethodDef PyCursesPanel_Methods[] = {
 /* -------------------------------------------------------*/
 
 static PyType_Slot PyCursesPanel_Type_slots[] = {
+    {Py_tp_new,     PyType_NullNew},
     {Py_tp_dealloc, PyCursesPanel_Dealloc},
     {Py_tp_methods, PyCursesPanel_Methods},
     {0, 0},
@@ -640,7 +641,6 @@ PyInit__curses_panel(void)
     v = PyType_FromSpec(&PyCursesPanel_Type_spec);
     if (v == NULL)
         goto fail;
-    ((PyTypeObject *)v)->tp_new = NULL;
     _curses_panelstate(m)->PyCursesPanel_Type = v;
 
     import_curses();
