comctl32/listbox: Use a helper function to check the selection state of an item.

dlls/comctl32/listbox.c

@@ -125,6 +125,11 @@ static TIMER_DIRECTION LISTBOX_Timer = LB_TIMER_NONE;
 
 static LRESULT LISTBOX_GetItemRect( const LB_DESCR *descr, INT index, RECT *rect );
 
+static BOOL is_item_selected( const LB_DESCR *descr, UINT index )
+{
+    return descr->items[index].selected;
+}
+
 /***********************************************************************
  *           LISTBOX_GetCurrentPageSize
  *
@@ -2763,7 +2768,7 @@ static LRESULT CALLBACK LISTBOX_WindowProc( HWND hwnd, UINT msg, WPARAM wParam,
     case LB_GETSEL:
         if (((INT)wParam < 0) || ((INT)wParam >= descr->nb_items))
             return LB_ERR;
-        return descr->items[wParam].selected;
+        return is_item_selected(descr, wParam);
 
     case LB_SETSEL:
         ret = LISTBOX_SetSelection( descr, lParam, wParam, FALSE );