fix(ui): make winbar work with floats and multigrid

src/nvim/os/input.c

@@ -183,7 +183,7 @@ void os_breakcheck(void)
   // We do not want screen_resize() to redraw here.
   // TODO(bfredl): we are already special casing redraw events, is this
   // hack still needed?
-  updating_screen++;
+  updating_screen = true;
 
   loop_poll_events(&main_loop, 0);
 

src/nvim/screen.c

@@ -5324,8 +5324,10 @@ static void win_redr_custom(win_T *wp, bool draw_winbar, bool draw_ruler)
     use_sandbox = was_set_insecurely(wp, "tabline", 0);
   } else if (draw_winbar) {
     stl = (char_u *)((*wp->w_p_wbr != NUL) ? wp->w_p_wbr : p_wbr);
-    row = wp->w_winrow;
-    col = wp->w_wincol;
+    row = -1;  // row zero is first row of text
+    col = 0;
+    grid = &wp->w_grid;
+    grid_adjust(&grid, &row, &col);
     fillchar = wp->w_p_fcs_chars.wbr;
     attr = (wp == curwin) ? HL_ATTR(HLF_WBR) : HL_ATTR(HLF_WBRNC);
     maxwidth = wp->w_width_inner;

src/nvim/window.c

@@ -6296,7 +6296,7 @@ void win_set_inner_size(win_T *wp)
 
 static int win_extra_height(win_T *wp)
 {
-  return wp->w_border_adj[0] + wp->w_border_adj[2];
+  return wp->w_border_adj[0] + wp->w_border_adj[2] + wp->w_winbar_height;
 }
 
 static int win_extra_width(win_T *wp)