From bcfb35f80d9d1f87d9fa6993c1d3bc35dd5db865 Mon Sep 17 00:00:00 2001
From: Berker Peksag <berker.peksag@gmail.com>
Date: Sat, 17 Sep 2016 23:22:06 +0300
Subject: [PATCH] Issue #26384: Fix UnboundLocalError in
 socket._sendfile_use_sendfile

---
 Lib/socket.py           |  2 +-
 Lib/test/test_socket.py | 19 +++++++++++++++++++
 Misc/NEWS               |  2 ++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/Lib/socket.py b/Lib/socket.py
index 6dddfe1d34b..a9cab32e31e 100644
--- a/Lib/socket.py
+++ b/Lib/socket.py
@@ -258,7 +258,7 @@ class socket(_socket.socket):
                 raise _GiveupOnSendfile(err)  # not a regular file
             try:
                 fsize = os.fstat(fileno).st_size
-            except OSError:
+            except OSError as err:
                 raise _GiveupOnSendfile(err)  # not a regular file
             if not fsize:
                 return 0  # empty file
diff --git a/Lib/test/test_socket.py b/Lib/test/test_socket.py
index 4b047ee76ab..c5975c8c9e5 100644
--- a/Lib/test/test_socket.py
+++ b/Lib/test/test_socket.py
@@ -1447,6 +1447,25 @@ class GeneralModuleTests(unittest.TestCase):
             self.assertEqual(s.family, 42424)
             self.assertEqual(s.type, 13331)
 
+    @unittest.skipUnless(hasattr(os, 'sendfile'), 'test needs os.sendfile()')
+    def test__sendfile_use_sendfile(self):
+        class File:
+            def __init__(self, fd):
+                self.fd = fd
+
+            def fileno(self):
+                return self.fd
+        with socket.socket() as sock:
+            fd = os.open(os.curdir, os.O_RDONLY)
+            os.close(fd)
+            with self.assertRaises(socket._GiveupOnSendfile):
+                sock._sendfile_use_sendfile(File(fd))
+            with self.assertRaises(OverflowError):
+                sock._sendfile_use_sendfile(File(2**1000))
+            with self.assertRaises(TypeError):
+                sock._sendfile_use_sendfile(File(None))
+
+
 @unittest.skipUnless(HAVE_SOCKET_CAN, 'SocketCan required for this test.')
 class BasicCANTest(unittest.TestCase):
 
diff --git a/Misc/NEWS b/Misc/NEWS
index 8fbdd226340..d3e9fd72e69 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -71,6 +71,8 @@ Core and Builtins
 Library
 -------
 
+- Fix UnboundLocalError in socket._sendfile_use_sendfile.
+
 - Issue #28075: Check for ERROR_ACCESS_DENIED in Windows implementation of
   os.stat().  Patch by Eryk Sun.