commit https://github.com/vim/vim/commit/e56bf15c163a921ce9e1c09c0d5b3a03efc63324 Author: Bram Moolenaar <Bram@vim.org> Date: Mon Feb 8 23:23:42 2016 +0100 patch 7.4.1293 Problem: Sometimes a channel may hang waiting for a message that was already discarded. (Ken Takata) Solution: Store the ID of the message blocking on in the channel.