From 5dba9e8aef544c0f10bda0ecbd965ac08d019f27 Mon Sep 17 00:00:00 2001
From: Guido van Rossum <guido@python.org>
Date: Fri, 10 Jul 1998 18:03:50 +0000
Subject: [PATCH] Add special case to PySequence_List() so that list() of a
 list is faster (using PyList_GetSlice()).  Also added a test for a NULL
 argument, as with PySequence_Tuple().  (Hmm...  Better names for these two
 would be PyList_FromSequence() and PyTuple_FromSequence().  Oh well.)

---
 Objects/abstract.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Objects/abstract.c b/Objects/abstract.c
index a94a1368c9d..cfa4cc839c8 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -1055,6 +1055,12 @@ PySequence_List(v)
 {
 	PySequenceMethods *m;
 
+	if (v == NULL)
+		return null_error();
+
+	if (PyList_Check(v))
+		return PyList_GetSlice(v, 0, PyList_GET_SIZE(v));
+
 	m = v->ob_type->tp_as_sequence;
 	if (m && m->sq_item) {
 		int i;