made cPickle fall back to the copy_reg/reduce protocol,

if a function cannot be stored as global.
This is for compatibility with pickle.py .

Modules/cPickle.c

@@ -2418,6 +2418,11 @@ save(Picklerobject *self, PyObject *args, int pers_save)
         case 'f':
 		if (type == &PyFunction_Type) {
 			res = save_global(self, args, NULL);
+			if (res && PyErr_ExceptionMatches(PickleError)) {
+				/* fall back to reduce */
+				PyErr_Clear();
+				break;
+			}
 			goto finally;
 		}
 		break;