Textalk/jquery.jsonrpcclient.js — pull request #24 by xa4a (2014-06-08 10:59:47+00:00)
Title: Don't consider response with {error: null} to be an error.

According to http://json-rpc.org/wiki/specification error:
> An Error object if there was an error invoking the method. It must be null if there was no error.