issue #121: fix call_function_test by not raising the dead

A first small mea culpa to all my testing sins of late :)

mitogen/core.py

@@ -294,7 +294,7 @@ class Message(object):
             self.pickled(obj, dst_id=self.src_id, **kwargs)
         )
 
-    def unpickle(self, throw=True):
+    def unpickle(self, throw=True, throw_dead=True):
         """Deserialize `data` into an object."""
         _vv and IOLOG.debug('%r.unpickle()', self)
         fp = cStringIO.StringIO(self.data)
@@ -308,7 +308,7 @@ class Message(object):
             raise StreamError('invalid message: %s', ex)
 
         if throw:
-            if obj == _DEAD:
+            if obj == _DEAD and throw_dead:
                 raise ChannelError(ChannelError.remote_msg)
             if isinstance(obj, CallError):
                 raise obj

mitogen/master.py

@@ -609,7 +609,8 @@ class Context(mitogen.core.Context):
         )
 
     def call(self, fn, *args, **kwargs):
-        return self.call_async(fn, *args, **kwargs).get().unpickle()
+        receiver = self.call_async(fn, *args, **kwargs)
+        return receiver.get().unpickle(throw_dead=False)
 
 
 class Router(mitogen.parent.Router):