Issue #18909: Fix _tkinter.tkapp.interpaddr() on Windows 64-bit, don't cast

64-bit pointer to long (32 bits).

Misc/NEWS

@@ -66,6 +66,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #18909: Fix _tkinter.tkapp.interpaddr() on Windows 64-bit, don't cast
+  64-bit pointer to long (32 bits).
+
 - Issue #18876: The FileIO.mode attribute now better reflects the actual mode
   under which the file was opened.  Patch by Erik Bray.
 

Modules/_tkinter.c

@@ -2688,7 +2688,7 @@ Tkapp_InterpAddr(PyObject *self, PyObject *args)
     if (!PyArg_ParseTuple(args, ":interpaddr"))
         return NULL;
 
-    return PyLong_FromLong((long)Tkapp_Interp(self));
+    return PyLong_FromVoidPtr(Tkapp_Interp(self));
 }
 
 static PyObject *