--- .//qtbase/src/widgets/widgets/qtabbar.cpp.orig	2023-03-14 04:29:43.000000000 -0400
+++ .//qtbase/src/widgets/widgets/qtabbar.cpp	2023-04-23 20:20:00.000000000 -0400
@@ -714,6 +714,8 @@
 {
     Q_Q(QTabBar);
     Q_ASSERT(index >= 0);
+    // play it safe
+    if (index < 0) return;
 
     const Tab *tab = tabList.at(index);
     bool vertical = verticalTabs(shape);
