vim-patch:7.4.1961

Problem:    When 'insertmode' is reset while doing completion the popup menu
            remains even though Vim is in Normal mode.
Solution:   Ignore stop_insert_mode when the popup menu is visible.  Don't set
            stop_insert_mode when 'insertmode' was already off. (Christian
            Brabandt)

00672e1d3f

src/nvim/edit.c

@@ -502,7 +502,7 @@ static int insert_check(VimState *state)
     Insstart_orig = Insstart;
   }
 
-  if (stop_insert_mode) {
+  if (stop_insert_mode && !pum_visible()) {
     // ":stopinsert" used or 'insertmode' reset
     s->count = 0;
     return 0;  // exit insert mode