No idea why we were hardcoding anything here, ever.

bitprophet · bitprophet · commit 5d0681afca4c · 2012-02-15T16:10:15.000-08:00
Caused fabric#303, and also breaks inside bpython, as it happens.
diff --git a/fabric/context_managers.py b/fabric/context_managers.py
@@ -325,7 +325,7 @@ def char_buffered(pipe):
 
     Only applies on Unix-based systems; on Windows this is a no-op.
     """
-    if win32 or not sys.stdin.isatty():
+    if win32 or not pipe.isatty():
         yield
     else:
         old_settings = termios.tcgetattr(pipe)
