Draft: Issue #3144382: When page is loaded via back button (persisted) re-enable disabled form submit button

Closes #3144382

core/misc/form.js

@@ -22,7 +22,7 @@
  * @event formFragmentLinkClickOrHashChange
  */
 
-(function ($, Drupal, debounce) {
+(function ($, window, Drupal, debounce) {
   /**
    * Retrieves the summary for the first element.
    *
@@ -141,6 +141,18 @@
         'form:not([method~="GET"])',
         onFormSubmit,
       );
+
+      // Binds a listener to clear stored form values from formSingleSubmit() when
+      // page is loaded from back/forward cache. This allows the form submission
+      // button to be used again instead of remaining disabled.
+      // Checking persisted does not work with jQuery on().
+      window.addEventListener('pageshow', (event) => {
+        if (event.persisted) {
+          $('form:not([method~="GET"])').removeAttr(
+            'data-drupal-form-submit-last',
+          );
+        }
+      });
     },
   };
 
@@ -331,4 +343,4 @@
     'a[href*="#"]',
     debouncedHandleFragmentLinkClickOrHashChange,
   );
-})(jQuery, Drupal, Drupal.debounce);
+})(jQuery, window, Drupal, Drupal.debounce);