Allow any buffer type to written to BufferedFile

Fixes #967

Also adds test coverage for writing various types to
BufferedFile which required some small changes to the test
LoopbackFile subclass.

Change against the 1.17 branch.

1 files changed, 5 insertions, 2 deletions

diff --git a/paramiko/file.py b/paramiko/file.py
index 5212091a..35637b8e 100644
--- a/paramiko/file.py
+++ b/paramiko/file.py
@@ -18,7 +18,7 @@
 from paramiko.common import (
     linefeed_byte_value, crlf, cr_byte, linefeed_byte, cr_byte_value,
 )
-from paramiko.py3compat import BytesIO, PY2, u, b, bytes_types
+from paramiko.py3compat import BytesIO, PY2, u, bytes_types, text_type
 
 from paramiko.util import ClosingContextManager
 
@@ -391,7 +391,10 @@ class BufferedFile (ClosingContextManager):
 
         :param data: ``str``/``bytes`` data to write
         """
-        data = b(data)
+        if isinstance(data, text_type):
+            # GZ 2017-05-25: Accepting text on a binary stream unconditionally
+            # cooercing to utf-8 seems questionable, but compatibility reasons?
+            data = data.encode('utf-8')
         if self._closed:
             raise IOError('File is closed')
         if not (self._flags & self.FLAG_WRITE):