Issue #3381033 by dcam, mfv: The default tab's LI wrapper can receive focus

js/quicktabs.js

@@ -42,7 +42,6 @@
     // Set clicked tab to active.
     $(this).parents('li').siblings().removeClass('active');
     $(this).parents('li').siblings().attr('aria-selected', 'false');
-    $(this).parents('li').siblings().attr('tabindex', '-1');
     $(this).parents('li').siblings().find('a').attr('tabindex', '-1');
     $(this).parents('li').addClass('active');
     $(this).parents('li').attr('aria-selected', 'true');

src/Plugin/TabRenderer/QuickTabs.php

@@ -143,12 +143,10 @@ class QuickTabs extends TabRendererBase {
         'aria-controls' => $block_id,
         'aria-selected' => 'false',
         'id' => $tab_id,
-        'tabIndex' => '-1',
       ];
       if ($default_tab == $index) {
         $wrapper_attributes['class'] = ['active'];
         $wrapper_attributes['aria-selected'] = 'true';
-        $wrapper_attributes['tabindex'] = '0';
       }
       if ($custom_class) {
         $wrapper_attributes['class'][] = $custom_class;
@@ -199,6 +197,7 @@ class QuickTabs extends TabRendererBase {
               'attributes' => [
                 'class' => $link_classes,
                 'data-quicktabs-tab-index' => $index,
+                'tabindex' => $default_tab == $index ? 0 : -1,
               ],
             ]
           )