Merge Martin[gz]'s fix for make_stream_binary.

1 files changed, 10 insertions, 4 deletions

diff --git a/python/subunit/__init__.py b/python/subunit/__init__.py
index 14fb94d..c997296 100644
--- a/python/subunit/__init__.py
+++ b/python/subunit/__init__.py
@@ -1075,7 +1075,6 @@ class ProtocolTestCase(object):
         _make_stream_binary(stream)
         self._passthrough = passthrough
         self._forward = forward
-        _make_stream_binary(forward)
 
     def __call__(self, result=None):
         return self.run(result)
@@ -1154,11 +1153,18 @@ def get_default_formatter():
         return sys.stdout
 
 
+if sys.version_info > (3, 0):
+    from io import UnsupportedOperation as _NoFilenoError
+else:
+    _NoFilenoError = AttributeError
+
 def _make_stream_binary(stream):
     """Ensure that a stream will be binary safe. See _make_binary_on_windows."""
-    if getattr(stream, 'fileno', None) is not None:
-        print (stream, type(stream))
-        _make_binary_on_windows(stream.fileno())
+    try:
+        fileno = stream.fileno()
+    except _NoFilenoError:
+        return
+    _make_binary_on_windows(fileno)
 
 def _make_binary_on_windows(fileno):
     """Win32 mangles \r\n to \n and that breaks streams. See bug lp:505078."""