patch 8.1.0792: bad display if opening cmdline window from Insert completion commit https://github.com/vim/vim/commit/9e26f7d31fbb780613fa700fe61de3e0b4ff2ef6 Author: Bram Moolenaar <Bram@vim.org> Date: Tue Jan 22 22:08:09 2019 +0100 patch 8.1.0792: bad display if opening cmdline window from Insert completion Problem: Popup menu is displayed on top of the cmdline window if it is opened from Insert completion. (Bjorn Linse) Solution: Remove the popup menu. Restore the cursor position. (closes #3838)

--- a/src/ex_getln.c
+++ b/src/ex_getln.c
@@ -7268,6 +7268,10 @@ open_cmdwin(void)
     /* Don't execute autocommands while creating the window. */
     block_autocmds();
 
+    // When using completion in Insert mode with <C-R>=<C-F> one can open the
+    // command line window, but we don't want the popup menu then.
+    pum_undisplay();
+
     /* don't use a new tab page */
     cmdmod.tab = 0;
     cmdmod.noswapfile = 1;