fix(input): put modifiers back into typeahead buffer when needed

src/nvim/message.c

@@ -1215,7 +1215,7 @@ void wait_return(int redraw)
     } else if (vim_strchr((char_u *)"\r\n ", c) == NULL && c != Ctrl_C) {
       // Put the character back in the typeahead buffer.  Don't use the
       // stuff buffer, because lmaps wouldn't work.
-      ins_char_typebuf(c);
+      ins_char_typebuf(c, mod_mask);
       do_redraw = true;             // need a redraw even though there is
                                     // typeahead
     }
@@ -3497,7 +3497,7 @@ int do_dialog(int type, char_u *title, char_u *message, char_u *buttons, int dfl
       }
       if (c == ':' && ex_cmd) {
         retval = dfltbutton;
-        ins_char_typebuf(':');
+        ins_char_typebuf(':', 0);
         break;
       }