python: Don't raise exception from Session.resume_data()

In practice, Session.resume_data() will be used without checking there
is deferred data or not. Actually, there is no API to check this.  So
it is better not to raise exception. Instead return False to notify
error. If the method succeeds, it returns True.

doc/python.rst

@@ -258,8 +258,9 @@ Session Objects
     Puts back previously deferred DATA frame in the stream *stream_id*
     to the outbound queue.
 
-    The :py:class:`InvalidArgumentError` will be raised if the stream
-    does not exist or no deferred data exist.
+    This method returns ``True`` if it succeeds, or ``False``.  This
+    method will fail if the stream does not exist or no deferred data
+    exist.
 
 .. py:method:: Session.want_read()
 

python/spdylay.pyx

@@ -778,9 +778,9 @@ cdef class Session:
         cpdef int rv
         rv = cspdylay.spdylay_session_resume_data(self._c_session, stream_id)
         if rv == 0:
-            return
+            return True
         elif rv == cspdylay.SPDYLAY_ERR_INVALID_ARGUMENT:
-            raise InvalidArgumentError(_strerror(rv))
+            return False
         elif rv == cspdylay.SPDYLAY_ERR_NOMEM:
             raise MemoryError()
 

python/spdylay_tests.py

@@ -174,8 +174,7 @@ class SpdylayTests(unittest.TestCase):
         self.assertEqual(spdylay.GOAWAY_PROTOCOL_ERROR, frame.status_code)
 
     def test_resume_data(self):
-        with self.assertRaises(spdylay.InvalidArgumentError):
-            self.client_session.resume_data(1)
+        self.assertFalse(self.client_session.resume_data(1))
 
     def test_get_pri_lowest(self):
         self.assertEqual(7, self.client_session.get_pri_lowest())