Issue #4838: When a module is deallocated, free the memory backing the optional module state data.

Misc/NEWS

@@ -12,6 +12,9 @@ What's New in Python 3.1 alpha 0
 Core and Builtins
 -----------------
 
+- Issue #4838: When a module is deallocated, free the memory backing the
+  optional module state data.
+
 - Issue #4910: Rename nb_long slot to nb_reserved, and change its
   type to (void *).
 

Objects/moduleobject.c

@@ -315,6 +315,8 @@ module_dealloc(PyModuleObject *m)
 		_PyModule_Clear((PyObject *)m);
 		Py_DECREF(m->md_dict);
 	}
+	if (m->md_state != NULL)
+		PyMem_FREE(m->md_state);
 	Py_TYPE(m)->tp_free((PyObject *)m);
 }