fix(Menu): prevent flyout crash when mixing keyboard and mouse interaction (#11993)

Author: kmcfaul

packages/react-core/src/components/Menu/Menu.tsx

@@ -183,7 +183,6 @@ class MenuBase extends Component<MenuProps, MenuState> {
       !(event.target as HTMLElement).classList.contains(breadcrumbStyles.breadcrumbLink)
     ) {
       this.activeMenu = (event.target as HTMLElement).closest(`.${styles.menu}`);
-      this.setState({ disableHover: true });
     }
 
     if ((event.target as HTMLElement).tagName === 'INPUT') {

packages/react-core/src/components/Menu/MenuItem.tsx

@@ -210,10 +210,10 @@ const MenuItemBase: React.FunctionComponent<MenuItemProps> = ({
     if (flyoutTarget) {
       if (flyoutVisible) {
         const flyoutMenu = (flyoutTarget as HTMLElement).nextElementSibling;
-        const flyoutItems = Array.from(flyoutMenu.getElementsByTagName('UL')[0].children).filter(
+        const flyoutItems = Array.from(flyoutMenu?.getElementsByTagName('UL')[0]?.children || []).filter(
           (el) => !(el.classList.contains('pf-m-disabled') || el.classList.contains(styles.divider))
         );
-        (flyoutItems[0].firstChild as HTMLElement).focus();
+        (flyoutItems[0]?.firstChild as HTMLElement)?.focus();
       } else {
         flyoutTarget.focus();
       }