add tp_clear for visited objects

Author: picnixz

Modules/_tkinter.c

@@ -2759,14 +2759,21 @@ Tktt_New(PyObject *func)
     return (TkttObject*)Py_NewRef(v);
 }
 
+static int
+Tktt_Clear(PyObject *op)
+{
+    TkttObject *self = TkttObject_CAST(op);
+    Py_CLEAR(self->func);
+    return 0;
+}
+
 static void
 Tktt_Dealloc(PyObject *op)
 {
     PyTypeObject *tp = Py_TYPE(op);
     PyObject_GC_UnTrack(op);
-    TkttObject *self = TkttObject_CAST(op);
-    Py_XDECREF(self->func);
-    tp->tp_free(self);
+    (void)Tktt_Clear(op);
+    tp->tp_free(op);
     Py_DECREF(tp);
 }
 
@@ -3069,6 +3076,14 @@ _tkinter_tkapp_willdispatch_impl(TkappObject *self)
 
 /**** Tkapp Type Methods ****/
 
+static int
+Tkapp_Clear(PyObject *op)
+{
+    TkappObject *self = TkappObject_CAST(op);
+    Py_CLEAR(self->trace);
+    return 0;
+}
+
 static void
 Tkapp_Dealloc(PyObject *op)
 {
@@ -3079,7 +3094,7 @@ Tkapp_Dealloc(PyObject *op)
     ENTER_TCL
     Tcl_DeleteInterp(Tkapp_Interp(self));
     LEAVE_TCL
-    Py_XDECREF(self->trace);
+    (void)Tkapp_Clear(op);
     tp->tp_free(self);
     Py_DECREF(tp);
     DisableEventHook();
@@ -3280,6 +3295,7 @@ static PyMethodDef Tktt_methods[] =
 };
 
 static PyType_Slot Tktt_Type_slots[] = {
+    {Py_tp_dealloc, Tktt_Clear},
     {Py_tp_dealloc, Tktt_Dealloc},
     {Py_tp_traverse, Tktt_Traverse},
     {Py_tp_repr, Tktt_Repr},
@@ -3340,6 +3356,7 @@ static PyMethodDef Tkapp_methods[] =
 };
 
 static PyType_Slot Tkapp_Type_slots[] = {
+    {Py_tp_dealloc, Tkapp_Clear},
     {Py_tp_dealloc, Tkapp_Dealloc},
     {Py_tp_traverse, Tkapp_Traverse},
     {Py_tp_methods, Tkapp_methods},