Issue #3403198 by simohell, mgifford, itmaybejj: Details do not benefit from aria-pressed

core/includes/form.inc

@@ -255,7 +255,6 @@ function template_preprocess_details(&$variables) {
       $variables['summary_attributes']['aria-controls'] = $element['#attributes']['id'];
     }
     $variables['summary_attributes']['aria-expanded'] = !empty($element['#attributes']['open']) ? 'true' : 'false';
-    $variables['summary_attributes']['aria-pressed'] = $variables['summary_attributes']['aria-expanded'];
   }
   $variables['title'] = (!empty($element['#title'])) ? $element['#title'] : '';
   // If the element title is a string, wrap it a render array so that markup

core/misc/details-aria.js

@@ -23,7 +23,6 @@
 
           $summary.attr({
             'aria-expanded': open,
-            'aria-pressed': open,
           });
         },
       );

core/tests/Drupal/FunctionalJavascriptTests/Core/Form/FormGroupingElementsTest.php

@@ -134,7 +134,6 @@ public function testDetailsChildVisibility() {
 
     // Assert that both aria-expanded and aria-pressed are true.
     $this->assertEquals('true', $summary->getAttribute('aria-expanded'));
-    $this->assertEquals('true', $summary->getAttribute('aria-pressed'));
   }
 
   /**