From f90eddef5d3554136623aa81a91187640bf0e92c Mon Sep 17 00:00:00 2001
From: Barry Warsaw <barry@python.org>
Date: Wed, 18 Dec 1996 19:32:18 +0000
Subject: [PATCH] PySequence_Index(): set exception when object is not found in
 sequence, otherwise

operator.indexOf([4, 3, 2, 1], 9) would raise a SystemError!

Note: it might be wise to double check all these functions.  I haven't
done that yet.
---
 Objects/abstract.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/Objects/abstract.c b/Objects/abstract.c
index a8823eb5a23..cac767fbfee 100644
--- a/Objects/abstract.c
+++ b/Objects/abstract.c
@@ -912,6 +912,7 @@ PySequence_Index(s, o)
       if(err) return -1;
       if(! not_equal) return i;
     }
+  PyErr_SetString(PyExc_ValueError, "list.index(x): x not in list");
   return -1;
 }