commit https://github.com/vim/vim/commit/cf7ff70ca73218d618e7c00ab785bcf5f9120a94 Author: Bram Moolenaar <Bram@vim.org> Date: Mon May 9 17:20:14 2016 +0200 patch 7.4.1826 Problem: Callbacks are invoked when it's not safe. (Andrew Stewart) Solution: When a channel is to be closed don't invoke callbacks right away, wait for a safe moment.