commit https://github.com/vim/vim/commit/f6157284de71d8881f3b89fbd79d1ecbf842929f Author: Bram Moolenaar <Bram@vim.org> Date: Wed Feb 10 21:07:14 2016 +0100 patch 7.4.1299 Problem: When the server sends a message with ID zero the channel handler is not invoked. (Christian J. Robinson) Solution: Recognize zero value for the request ID. Add a test for invoking the channel handler.