Add missing readable/writable methods to FileObjectPosix. Fixes at least...

Add missing readable/writable methods to FileObjectPosix. Fixes at least help() on a monkey-patched Python 3

changelog.rst

@@ -15,7 +15,8 @@ Unreleased
   Reported in :issue:`623` by Jonathan Kamens.
 - Various fixes on Windows. Reported in :issue:`625`, :issue:`627`,
   and :issue:`628` by jacekt and Yuanteng (Jeff) Pei. Fixed in :pr:`624`.
-
+- Add ``readable`` and ``writable`` methods to ``FileObjectPosix``;
+  this fixes e.g., help() on Python 3 when monkey-patched.
 
 1.1b1 (Jul 17, 2015)
 ====================

gevent/_fileobjectposix.py

@@ -216,6 +216,12 @@ class FileObjectPosix(object):
     def readlines(self, sizehint=0):
         return self.io.readlines(sizehint)
 
+    def readable(self):
+        return self.io.readable()
+
+    def writable(self):
+        return self.io.writable()
+
     def seek(self, *args, **kwargs):
         return self.io.seek(*args, **kwargs)
 
@@ -232,4 +238,6 @@ class FileObjectPosix(object):
         return self.io
 
     def __getattr__(self, name):
+        # XXX: Should this really be _fobj, or self.io?
+        # _fobj can easily be None but io never is
         return getattr(self._fobj, name)