exporting patch:
# HG changeset patch
# User anatoly techtonik <techtonik@gmail.com>
# Date 1271273064 -10800
# Node ID 9fea147a78a0747f9b5b12199e2a78b7231192ea
# Parent  2092e63f68d97ba5677d9495556aa37b79ac0aeb
fix bug #557585 GitFile breaks dulwich on Windows
fix is to add os.O_BINARY flag as os.open doesn't open files as binary
on this platform by default

diff -r 2092e63f68d9 -r 9fea147a78a0 dulwich/file.py
--- a/dulwich/file.py	Wed Apr 07 23:59:26 2010 +0300
+++ b/dulwich/file.py	Wed Apr 14 22:24:24 2010 +0300
@@ -52,7 +52,11 @@
     def __init__(self, filename, mode, bufsize):
         self._filename = filename
         self._lockfilename = '%s.lock' % self._filename
-        fd = os.open(self._lockfilename, os.O_RDWR | os.O_CREAT | os.O_EXCL)
+
+        flags = os.O_RDWR | os.O_CREAT | os.O_EXCL
+        if os.name == 'nt':
+            flags = flags | os.O_BINARY
+        fd = os.open(self._lockfilename, flags)
         self._file = os.fdopen(fd, mode, bufsize)
 
         for method in self.PROXY_METHODS: