From 2174dcb06187098ceecad4e932ddfc95ffc36612 Mon Sep 17 00:00:00 2001
From: Guido van Rossum <guido@python.org>
Date: Wed, 15 Sep 1999 22:48:09 +0000
Subject: [PATCH] Tim Peters writes:

For a long time I've seen absurd tracebacks under -O (e.g., negative
line numbers), but very rarely.  Since I was looking at tracebacks
anyway, thought I'd track it down.  Turns out to be Guido's only
predictable blind spot <wink -- "char" is signed on some non-GvR
systems>.  Patch follows.
---
 Python/compile.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Python/compile.c b/Python/compile.c
index 1e937e492ab..e4e37d53f8c 100644
--- a/Python/compile.c
+++ b/Python/compile.c
@@ -3451,7 +3451,7 @@ PyCode_Addr2Line(co, addrq)
 	int addrq;
 {
 	int size = PyString_Size(co->co_lnotab) / 2;
-	char *p = PyString_AsString(co->co_lnotab);
+	unsigned char *p = (unsigned char*)PyString_AsString(co->co_lnotab);
 	int line = co->co_firstlineno;
 	int addr = 0;
 	while (--size >= 0) {