Fix flicker when opening/closing submenus

term_util.c

@@ -181,6 +181,10 @@ void qmenu_free(Qmenu* qm) {
 }
 
 void qnav_free_block(Qblock* qb) {
+  // erase any stuff underneath where this window is, in case it's outside of
+  // the grid in an area that isn't actively redraw
+  werase(qb->outer_window);
+  wnoutrefresh(qb->outer_window);
   switch (qb->tag) {
   case Qblock_type_qmsg: {
     Qmsg* qm = qmsg_of(qb);

tui_main.c

@@ -1726,10 +1726,8 @@ int main(int argc, char** argv) {
       ged_apply_delta_secs(&ged_state, stm_sec(diff));
       ged_do_stuff(&ged_state);
       bool drew_any = false;
-      if (qnav_stack.stack_changed) {
-        werase(stdscr);
+      if (qnav_stack.stack_changed)
         drew_any = true;
-      }
       if (ged_is_draw_dirty(&ged_state) || drew_any) {
         werase(cont_window);
         ged_draw(&ged_state, cont_window);