diff --git a/core/lib/Drupal/Core/Form/FormBuilder.php b/core/lib/Drupal/Core/Form/FormBuilder.php
index d16d851..524e71d 100644
--- a/core/lib/Drupal/Core/Form/FormBuilder.php
+++ b/core/lib/Drupal/Core/Form/FormBuilder.php
@@ -398,6 +398,10 @@ public function retrieveForm($form_id, FormStateInterface &$form_state) {
       $form['#attributes']['class'][] = Html::getClass($build_info['base_form_id']);
     }
 
+    // Make sure misc/form.js is included in all forms.
+    // This is important to prevent multiple form submits (@see Drupal.behaviors.formSingleSubmit).
+    $form['#attached']['library'][] = 'core/drupal.form';
+
     // We need to pass $form_state by reference in order for forms to modify it,
     // since call_user_func_array() requires that referenced variables are
     // passed explicitly.
diff --git a/core/misc/form.js b/core/misc/form.js
index b1d1fff..4b1b53a 100644
--- a/core/misc/form.js
+++ b/core/misc/form.js
@@ -170,32 +170,4 @@
     }
   };
 
-  /**
-   * Prepopulate form fields with information from the visitor browser.
-   */
-  Drupal.behaviors.fillUserInfoFromBrowser = {
-    attach: function (context, settings) {
-      var userInfo = ['name', 'mail', 'homepage'];
-      var $forms = $('[data-user-info-from-browser]').once('user-info-from-browser');
-      if ($forms.length) {
-        userInfo.map(function (info) {
-          var $element = $forms.find('[name=' + info + ']');
-          var browserData = localStorage.getItem('Drupal.visitor.' + info);
-          var emptyOrDefault = ($element.val() === '' || ($element.attr('data-drupal-default-value') === $element.val()));
-          if ($element.length && emptyOrDefault && browserData) {
-            $element.val(browserData);
-          }
-        });
-      }
-      $forms.on('submit', function () {
-        userInfo.map(function (info) {
-          var $element = $forms.find('[name=' + info + ']');
-          if ($element.length) {
-            localStorage.setItem('Drupal.visitor.' + info, $element.val());
-          }
-        });
-      });
-    }
-  };
-
 })(jQuery, Drupal, Drupal.debounce);
diff --git a/core/modules/comment/src/CommentForm.php b/core/modules/comment/src/CommentForm.php
index a9d742b..658f5ef 100644
--- a/core/modules/comment/src/CommentForm.php
+++ b/core/modules/comment/src/CommentForm.php
@@ -87,7 +87,7 @@ public function form(array $form, FormStateInterface $form_state) {
     $is_admin = $comment->id() && $this->currentUser->hasPermission('administer comments');
 
     if (!$this->currentUser->isAuthenticated() && $anonymous_contact != COMMENT_ANONYMOUS_MAYNOT_CONTACT) {
-      $form['#attached']['library'][] = 'core/drupal.form';
+      $form['#attached']['library'][] = 'user/drupal.user.fill';
       $form['#attributes']['data-user-info-from-browser'] = TRUE;
     }
 
diff --git a/core/modules/contact/src/MessageForm.php b/core/modules/contact/src/MessageForm.php
index 908ed17..5ab7616 100644
--- a/core/modules/contact/src/MessageForm.php
+++ b/core/modules/contact/src/MessageForm.php
@@ -109,7 +109,7 @@ public function form(array $form, FormStateInterface $form_state) {
       '#required' => TRUE,
     );
     if ($user->isAnonymous()) {
-      $form['#attached']['library'][] = 'core/drupal.form';
+      $form['#attached']['library'][] = 'user/drupal.user.fill';
       $form['#attributes']['data-user-info-from-browser'] = TRUE;
     }
     // Do not allow authenticated users to alter the name or email values to
diff --git a/core/modules/user/src/RegisterForm.php b/core/modules/user/src/RegisterForm.php
index bbf131e..aa786d7 100644
--- a/core/modules/user/src/RegisterForm.php
+++ b/core/modules/user/src/RegisterForm.php
@@ -40,7 +40,7 @@ public function form(array $form, FormStateInterface $form_state) {
       '#value' => $admin,
     );
 
-    $form['#attached']['library'][] = 'core/drupal.form';
+    $form['#attached']['library'][] = 'user/drupal.user.fill';
 
     // For non-admin users, populate the form fields using data from the
     // browser.
diff --git a/core/modules/user/user.fill.js b/core/modules/user/user.fill.js
new file mode 100644
index 0000000..47bcf9b
--- /dev/null
+++ b/core/modules/user/user.fill.js
@@ -0,0 +1,33 @@
+(function ($) {
+
+  "use strict";
+
+  /**
+   * Prepopulate form fields with information from the visitor browser.
+   */
+  Drupal.behaviors.fillUserInfoFromBrowser = {
+    attach: function (context, settings) {
+      var userInfo = ['name', 'mail', 'homepage'];
+      var $forms = $('[data-user-info-from-browser]').once('user-info-from-browser');
+      if ($forms.length) {
+        userInfo.map(function (info) {
+          var $element = $forms.find('[name=' + info + ']');
+          var browserData = localStorage.getItem('Drupal.visitor.' + info);
+          var emptyOrDefault = ($element.val() === '' || ($element.attr('data-drupal-default-value') === $element.val()));
+          if ($element.length && emptyOrDefault && browserData) {
+            $element.val(browserData);
+          }
+        });
+      }
+      $forms.on('submit', function () {
+        userInfo.map(function (info) {
+          var $element = $forms.find('[name=' + info + ']');
+          if ($element.length) {
+            localStorage.setItem('Drupal.visitor.' + info, $element.val());
+          }
+        });
+      });
+    }
+  };
+
+})(jQuery);
diff --git a/core/modules/user/user.libraries.yml b/core/modules/user/user.libraries.yml
index 037023a..d8e5cae 100644
--- a/core/modules/user/user.libraries.yml
+++ b/core/modules/user/user.libraries.yml
@@ -32,3 +32,10 @@ drupal.user.icons:
   css:
     theme:
       css/user.icons.css: {}
+
+drupal.user.fill:
+  version: VERSION
+  js:
+    user.fill.js: {}
+  dependencies:
+    - core/drupal.form