patch 8.2.0670: cannot change window when evaluating 'completefunc' Commit: https://github.com/vim/vim/commit/6adb9ea0a6ca01414f4b591f379b0f829a8273c0 Author: Bram Moolenaar <Bram@vim.org> Date: Thu Apr 30 22:31:18 2020 +0200 patch 8.2.0670: cannot change window when evaluating 'completefunc' Problem: Cannot change window when evaluating 'completefunc'. Solution: Make a difference between not changing text or buffers and also not changing window.

--- a/src/undo.c
+++ b/src/undo.c
@@ -331,7 +331,7 @@ undo_allowed(void)
 
     // Don't allow changes in the buffer while editing the cmdline.  The
     // caller of getcmdline() may get confused.
-    if (textlock != 0)
+    if (textwinlock != 0 || textlock != 0)
     {
 	emsg(_(e_textlock));
 	return FALSE;