commit https://github.com/vim/vim/commit/32b808a4bdf35b0dea63c735702a591e5869fecd Author: Bram Moolenaar <Bram@vim.org> Date: Sat Jul 9 21:57:20 2016 +0200 patch 7.4.2014 Problem: Using "noinsert" in 'completeopt' does not insert match. Solution: Set compl_enter_selects. (Shougo, closes https://github.com/vim/vim/issues/875)

--- a/src/edit.c
+++ b/src/edit.c
@@ -2831,6 +2831,7 @@ set_completion(colnr_T startcol, list_T 
     }
     else
 	ins_complete(Ctrl_N, FALSE);
+    compl_enter_selects = compl_no_insert;
 
     /* Lazily show the popup menu, unless we got interrupted. */
     if (!compl_interrupted)