export: do not print '<fdopen>' as an output filename Because makefileobj() duplicates or wraps stdout, "fp != sys.stdout" didn't work correctly. Python doc states that special file objects are named in the form '<...>', and absolute filenames should never start with '<', we can ignore names start with '<'. We can't test fp.fileno() because fp may be a command-server channel. https://docs.python.org/2.7/library/stdtypes.html#file.name In the test output, "exporting patch:" line is printed after patch content. This is caused by fdopen() and will be fixed by the subsequent patch.