patch 8.1.1321: no docs or tests for listener functions commit https://github.com/vim/vim/commit/a334772967de25764ed7b11d768e8b977818d0c6 Author: Bram Moolenaar <Bram@vim.org> Date: Sat May 11 21:14:24 2019 +0200 patch 8.1.1321: no docs or tests for listener functions Problem: No docs or tests for listener functions. Solution: Add help and tests for listener_add() and listener_remove(). Invoke the callbacks before redrawing.

--- a/src/screen.c
+++ b/src/screen.c
@@ -564,6 +564,11 @@ update_screen(int type_arg)
 	type = 0;
     }
 
+#ifdef FEAT_EVAL
+    // Before updating the screen, notify any listeners of changed text.
+    invoke_listeners();
+#endif
+
     if (must_redraw)
     {
 	if (type < must_redraw)	    /* use maximal type */