From 99da1f3afd30246512f48116962474c159c37398 Mon Sep 17 00:00:00 2001
From: Stefan Behnel <scoder@users.berlios.de>
Date: Tue, 15 Sep 2009 14:12:40 +0200
Subject: [PATCH] always optimise tuple(some_list), not only for literals

---
 Cython/Compiler/Optimize.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Cython/Compiler/Optimize.py b/Cython/Compiler/Optimize.py
index 261f6c14..425c7f6e 100644
--- a/Cython/Compiler/Optimize.py
+++ b/Cython/Compiler/Optimize.py
@@ -667,8 +667,9 @@ class OptimizeBuiltinCalls(Visitor.VisitorTransform):
             return node
         if not isinstance(list_arg, (ExprNodes.ComprehensionNode,
                                      ExprNodes.ListNode)):
-            # everything else may be None => take the safe path
-            return node
+            pos_args.args[0] = ExprNodes.NoneCheckNode(
+                list_arg, "PyExc_TypeError",
+                "'NoneType' object is not iterable")
 
         return ExprNodes.PythonCapiCallNode(
             node.pos, "PyList_AsTuple", self.PyList_AsTuple_func_type,
-- 
2.26.2