From bb09b212505a70a2b9f43ee2df6dd3ddb09776c1 Mon Sep 17 00:00:00 2001
From: Guido van Rossum <guido@python.org>
Date: Sun, 18 Mar 2007 03:36:28 +0000
Subject: [PATCH] Bug 1679498: unset variable 'bs'.

---
 Lib/io.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Lib/io.py b/Lib/io.py
index e4e67596872..59c4b062348 100644
--- a/Lib/io.py
+++ b/Lib/io.py
@@ -91,6 +91,8 @@ def open(filename, mode="r", buffering=None, *, encoding=None):
         try:
             bs = os.fstat(raw.fileno()).st_blksize
         except (os.error, AttributeError):
+            pass
+        else:
             if bs > 1:
                 buffering = bs
     if buffering < 0: