patch 8.0.1411: reading invalid memory with CTRL-W : commit https://github.com/vim/vim/commit/2efb323e875d2852f63e41c40641760d1d6b069f Author: Bram Moolenaar <Bram@vim.org> Date: Tue Dec 19 12:27:23 2017 +0100 patch 8.0.1411: reading invalid memory with CTRL-W : Problem: Reading invalid memory with CTRL-W :. Solution: Correct the command characters. (closes https://github.com/vim/vim/issues/2469)

--- a/src/normal.c
+++ b/src/normal.c
@@ -7850,8 +7850,12 @@ n_start_visual_mode(int c)
 nv_window(cmdarg_T *cap)
 {
     if (cap->nchar == ':')
+    {
 	/* "CTRL-W :" is the same as typing ":"; useful in a terminal window */
+	cap->cmdchar = ':';
+	cap->nchar = NUL;
 	nv_colon(cap);
+    }
     else if (!checkclearop(cap->oap))
 	do_window(cap->nchar, cap->count0, NUL); /* everything is in window.c */
 }