diff --git a/composer.json b/composer.json
index a6251b0787..9140ef0ba6 100644
--- a/composer.json
+++ b/composer.json
@@ -27,8 +27,8 @@
         "phpunit/phpunit": "^8.5.14 || ^9",
         "phpspec/prophecy": "^1.12",
         "symfony/css-selector": "^4.4",
-        "symfony/phpunit-bridge": "^5.3.0-rc1",
-        "symfony/var-dumper": "^5.3.0-rc1",
+        "symfony/phpunit-bridge": "^5.1.4",
+        "symfony/var-dumper": "^5.1.2",
         "symfony/error-handler": "^4.4",
         "justinrainbow/json-schema": "^5.2",
         "symfony/filesystem": "^4.4",
diff --git a/composer.lock b/composer.lock
index a0557a0147..6ddd74174b 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "9caab8f13f1024c45a4184d7c351370c",
+    "content-hash": "a21f5caf56f7a0d3a198f41c3fb84eac",
     "packages": [
         {
             "name": "asm89/stack-cors",
@@ -534,7 +534,7 @@
             "dist": {
                 "type": "path",
                 "url": "core",
-                "reference": "454ec5a15af2123c790974d1ad622bbb8ed61ec5"
+                "reference": "8c4a55a02c2380b587e1d59919848c0305c237ff"
             },
             "require": {
                 "asm89/stack-cors": "^1.1",
@@ -569,7 +569,7 @@
                 "symfony/event-dispatcher": "^4.4",
                 "symfony/http-foundation": "^4.4.7",
                 "symfony/http-kernel": "^4.4",
-                "symfony/mime": "^5.3.0-rc1",
+                "symfony/mime": "^5.2",
                 "symfony/polyfill-iconv": "^1.0",
                 "symfony/process": "^4.4",
                 "symfony/psr-http-message-bridge": "^2.0",
@@ -2996,16 +2996,16 @@
         },
         {
             "name": "symfony/mime",
-            "version": "v5.3.0-RC1",
+            "version": "v5.2.9",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/mime.git",
-                "reference": "0c3daded809edda4adee7179122a2a98069d8df7"
+                "reference": "64258e870f8cc75c3dae986201ea2df58c210b52"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/mime/zipball/0c3daded809edda4adee7179122a2a98069d8df7",
-                "reference": "0c3daded809edda4adee7179122a2a98069d8df7",
+                "url": "https://api.github.com/repos/symfony/mime/zipball/64258e870f8cc75c3dae986201ea2df58c210b52",
+                "reference": "64258e870f8cc75c3dae986201ea2df58c210b52",
                 "shasum": ""
             },
             "require": {
@@ -3059,7 +3059,7 @@
                 "mime-type"
             ],
             "support": {
-                "source": "https://github.com/symfony/mime/tree/v5.3.0-RC1"
+                "source": "https://github.com/symfony/mime/tree/v5.2.9"
             },
             "funding": [
                 {
@@ -3075,7 +3075,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2021-05-16T13:08:56+00:00"
+            "time": "2021-05-16T13:07:46+00:00"
         },
         {
             "name": "symfony/polyfill-ctype",
@@ -4252,16 +4252,16 @@
         },
         {
             "name": "symfony/var-dumper",
-            "version": "v5.3.0-RC1",
+            "version": "v5.2.8",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/var-dumper.git",
-                "reference": "29988c9bcac7bb66a03f00a2adaae131778db61c"
+                "reference": "d693200a73fae179d27f8f1b16b4faf3e8569eba"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/var-dumper/zipball/29988c9bcac7bb66a03f00a2adaae131778db61c",
-                "reference": "29988c9bcac7bb66a03f00a2adaae131778db61c",
+                "url": "https://api.github.com/repos/symfony/var-dumper/zipball/d693200a73fae179d27f8f1b16b4faf3e8569eba",
+                "reference": "d693200a73fae179d27f8f1b16b4faf3e8569eba",
                 "shasum": ""
             },
             "require": {
@@ -4320,7 +4320,7 @@
                 "dump"
             ],
             "support": {
-                "source": "https://github.com/symfony/var-dumper/tree/v5.3.0-RC1"
+                "source": "https://github.com/symfony/var-dumper/tree/v5.2.8"
             },
             "funding": [
                 {
@@ -4336,7 +4336,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2021-05-07T14:34:05+00:00"
+            "time": "2021-05-07T13:42:21+00:00"
         },
         {
             "name": "symfony/yaml",
@@ -7810,26 +7810,26 @@
         },
         {
             "name": "symfony/phpunit-bridge",
-            "version": "v5.3.0-RC1",
+            "version": "v5.2.9",
             "source": {
                 "type": "git",
                 "url": "https://github.com/symfony/phpunit-bridge.git",
-                "reference": "f2ecbe9ce01a91dac62356560f1cc903ab689de0"
+                "reference": "ea24e42c1ee04792f5d814da6f0814b20ece2907"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/symfony/phpunit-bridge/zipball/f2ecbe9ce01a91dac62356560f1cc903ab689de0",
-                "reference": "f2ecbe9ce01a91dac62356560f1cc903ab689de0",
+                "url": "https://api.github.com/repos/symfony/phpunit-bridge/zipball/ea24e42c1ee04792f5d814da6f0814b20ece2907",
+                "reference": "ea24e42c1ee04792f5d814da6f0814b20ece2907",
                 "shasum": ""
             },
             "require": {
-                "php": ">=7.1.3",
-                "symfony/deprecation-contracts": "^2.1"
+                "php": ">=5.5.9"
             },
             "conflict": {
-                "phpunit/phpunit": "<7.5|9.1.2"
+                "phpunit/phpunit": "<4.8.35|<5.4.3,>=5.0|<6.4,>=6.0|9.1.2"
             },
             "require-dev": {
+                "symfony/deprecation-contracts": "^2.1",
                 "symfony/error-handler": "^4.4|^5.0"
             },
             "suggest": {
@@ -7873,7 +7873,7 @@
             "description": "Provides utilities for PHPUnit, especially user deprecation notices management",
             "homepage": "https://symfony.com",
             "support": {
-                "source": "https://github.com/symfony/phpunit-bridge/tree/v5.3.0-RC1"
+                "source": "https://github.com/symfony/phpunit-bridge/tree/v5.2.9"
             },
             "funding": [
                 {
@@ -7889,7 +7889,7 @@
                     "type": "tidelift"
                 }
             ],
-            "time": "2021-05-16T13:08:56+00:00"
+            "time": "2021-05-16T13:07:46+00:00"
         },
         {
             "name": "theseer/tokenizer",
diff --git a/composer/Metapackage/CoreRecommended/composer.json b/composer/Metapackage/CoreRecommended/composer.json
index e5dbaa3207..b9c77d17fb 100644
--- a/composer/Metapackage/CoreRecommended/composer.json
+++ b/composer/Metapackage/CoreRecommended/composer.json
@@ -45,7 +45,7 @@
         "symfony/http-client-contracts": "v2.4.0",
         "symfony/http-foundation": "v4.4.23",
         "symfony/http-kernel": "v4.4.24",
-        "symfony/mime": "v5.3.0-RC1",
+        "symfony/mime": "v5.2.9",
         "symfony/polyfill-ctype": "v1.22.1",
         "symfony/polyfill-iconv": "v1.22.1",
         "symfony/polyfill-intl-idn": "v1.22.1",
@@ -60,7 +60,7 @@
         "symfony/translation": "v4.4.24",
         "symfony/translation-contracts": "v2.4.0",
         "symfony/validator": "v4.4.24",
-        "symfony/var-dumper": "v5.3.0-RC1",
+        "symfony/var-dumper": "v5.2.8",
         "symfony/yaml": "v4.4.24",
         "twig/twig": "v2.14.6",
         "typo3/phar-stream-wrapper": "v3.1.6"
diff --git a/composer/Metapackage/DevDependencies/composer.json b/composer/Metapackage/DevDependencies/composer.json
index 9eb0f0edeb..b9458d39b5 100644
--- a/composer/Metapackage/DevDependencies/composer.json
+++ b/composer/Metapackage/DevDependencies/composer.json
@@ -27,7 +27,7 @@
         "symfony/filesystem": "^4.4",
         "symfony/finder": "^4.4",
         "symfony/lock": "^4.4",
-        "symfony/phpunit-bridge": "^5.3.0-rc1",
-        "symfony/var-dumper": "^5.3.0-rc1"
+        "symfony/phpunit-bridge": "^5.1.4",
+        "symfony/var-dumper": "^5.1.2"
     }
 }
diff --git a/composer/Metapackage/PinnedDevDependencies/composer.json b/composer/Metapackage/PinnedDevDependencies/composer.json
index f99fbae1b3..f769a5fc4b 100644
--- a/composer/Metapackage/PinnedDevDependencies/composer.json
+++ b/composer/Metapackage/PinnedDevDependencies/composer.json
@@ -60,7 +60,7 @@
         "symfony/filesystem": "v4.4.22",
         "symfony/finder": "v4.4.24",
         "symfony/lock": "v4.4.23",
-        "symfony/phpunit-bridge": "v5.3.0-RC1",
+        "symfony/phpunit-bridge": "v5.2.9",
         "theseer/tokenizer": "1.2.0",
         "webmozart/assert": "1.10.0"
     }
diff --git a/core/composer.json b/core/composer.json
index b0677e756a..80d56099db 100644
--- a/core/composer.json
+++ b/core/composer.json
@@ -23,7 +23,7 @@
         "symfony/event-dispatcher": "^4.4",
         "symfony/http-foundation": "^4.4.7",
         "symfony/http-kernel": "^4.4",
-        "symfony/mime": "^5.3.0-rc1",
+        "symfony/mime": "^5.2",
         "symfony/routing": "^4.4",
         "symfony/serializer": "^4.4",
         "symfony/translation": "^4.4",
diff --git a/core/lib/Drupal/Component/Utility/Mail.php b/core/lib/Drupal/Component/Utility/Mail.php
index 50c998686c..423cfb2668 100644
--- a/core/lib/Drupal/Component/Utility/Mail.php
+++ b/core/lib/Drupal/Component/Utility/Mail.php
@@ -2,8 +2,6 @@
 
 namespace Drupal\Component\Utility;
 
-@trigger_error('\Drupal\Component\Utility\Mail is deprecated in drupal:9.2.0 and is removed from drupal:10.0.0. See https://www.drupal.org/node/3207439', E_USER_DEPRECATED);
-
 /**
  * Provides helpers to ensure emails are compliant with RFCs.
  *
@@ -31,15 +29,8 @@ class Mail {
    * @return string
    *   A RFC compliant version of the string, ready to be used as
    *   "display-name" in mail originator header fields.
-   *
-   * @deprecated in drupal:9.2.0 and is removed from drupal:10.0.0. Use
-   *   \Symfony\Component\Mime\Header\MailboxHeader instead.
-   *
-   * @see https://www.drupal.org/node/3207439
    */
   public static function formatDisplayName($string) {
-    @trigger_error('\Drupal\Component\Utility\Mail::formatDisplayName() is deprecated in drupal:9.2.0 and is removed from drupal:10.0.0. Use \Symfony\Component\Mime\Header\MailboxHeader instead. See https://www.drupal.org/node/3207439', E_USER_DEPRECATED);
-
     // Make sure we don't process html-encoded characters. They may create
     // unneeded trouble if left encoded, besides they will be correctly
     // processed if decoded.
diff --git a/core/lib/Drupal/Component/Utility/Unicode.php b/core/lib/Drupal/Component/Utility/Unicode.php
index 4a63ec2e47..a33250f935 100644
--- a/core/lib/Drupal/Component/Utility/Unicode.php
+++ b/core/lib/Drupal/Component/Utility/Unicode.php
@@ -393,14 +393,8 @@ public static function strcasecmp($str1, $str2) {
    *
    * @return string
    *   The mime-encoded header.
-   *
-   * @deprecated in drupal:9.2.0 and is removed from drupal:10.0.0. Use
-   *   \Symfony\Component\Mime\Header\UnstructuredHeader instead.
-   *
-   * @see https://www.drupal.org/node/3207439
    */
   public static function mimeHeaderEncode($string, $shorten = FALSE) {
-    @trigger_error('\Drupal\Component\Utility\Unicode::mimeHeaderEncode() is deprecated in drupal:9.2.0 and is removed from drupal:10.0.0. Use \Symfony\Component\Mime\Header\UnstructuredHeader instead. See https://www.drupal.org/node/3207439', E_USER_DEPRECATED);
     if (preg_match('/[^\x20-\x7E]/', $string)) {
       // floor((75 - strlen("=?UTF-8?B??=")) * 0.75);
       $chunk_size = 47;
@@ -429,14 +423,8 @@ public static function mimeHeaderEncode($string, $shorten = FALSE) {
    *
    * @return string
    *   The mime-decoded header.
-   *
-   * @deprecated in drupal:9.2.0 and is removed from drupal:10.0.0. Use
-   *   iconv_mime_decode() instead.
-   *
-   * @see https://www.drupal.org/node/3207439
    */
   public static function mimeHeaderDecode($header) {
-    @trigger_error('\Drupal\Component\Utility\Unicode::mimeHeaderDecode() is deprecated in drupal:9.2.0 and is removed from drupal:10.0.0. Use iconv_mime_decode() instead. See https://www.drupal.org/node/3207439', E_USER_DEPRECATED);
     $callback = function ($matches) {
       $data = (strtolower($matches[2]) == 'b') ? base64_decode($matches[3]) : str_replace('_', ' ', quoted_printable_decode($matches[3]));
       if (strtolower($matches[1]) != 'utf-8') {
diff --git a/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php b/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php
index b5cc94d668..875c9d3ef9 100644
--- a/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php
+++ b/core/lib/Drupal/Core/Ajax/AjaxResponseAttachmentsProcessor.php
@@ -128,7 +128,7 @@ public function processAttachments(AttachmentsInterface $response) {
    *   An array of commands ready to be returned as JSON.
    */
   protected function buildAttachmentsCommands(AjaxResponse $response, Request $request) {
-    $ajax_page_state = $request->request->all('ajax_page_state');
+    $ajax_page_state = $request->request->get('ajax_page_state');
 
     // Aggregate CSS/JS if necessary, but only during normal site operation.
     $optimize_css = !defined('MAINTENANCE_MODE') && $this->config->get('css.preprocess');
diff --git a/core/lib/Drupal/Core/Cache/Context/QueryArgsCacheContext.php b/core/lib/Drupal/Core/Cache/Context/QueryArgsCacheContext.php
index d9e5d67983..a48664468d 100644
--- a/core/lib/Drupal/Core/Cache/Context/QueryArgsCacheContext.php
+++ b/core/lib/Drupal/Core/Cache/Context/QueryArgsCacheContext.php
@@ -31,7 +31,7 @@ public function getContext($query_arg = NULL) {
       return ($value !== NULL) ? $value : '';
     }
     elseif ($this->requestStack->getCurrentRequest()->query->has($query_arg)) {
-      $value = $this->requestStack->getCurrentRequest()->query->all()[$query_arg];
+      $value = $this->requestStack->getCurrentRequest()->query->get($query_arg);
       if (is_array($value)) {
         return http_build_query($value);
       }
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/LanguageFormatter.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/LanguageFormatter.php
index 6f3c7cac44..93c5387e98 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/LanguageFormatter.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/LanguageFormatter.php
@@ -2,6 +2,7 @@
 
 namespace Drupal\Core\Field\Plugin\Field\FieldFormatter;
 
+use Drupal\Core\Entity\EntityTypeBundleInfoInterface;
 use Drupal\Core\Entity\EntityTypeManagerInterface;
 use Drupal\Core\Field\FieldDefinitionInterface;
 use Drupal\Core\Field\FieldItemInterface;
@@ -49,11 +50,13 @@ class LanguageFormatter extends StringFormatter {
    *   Any third party settings settings.
    * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
    *   The entity type manager.
+   * @param \Drupal\Core\Entity\EntityTypeBundleInfoInterface $entity_type_bundle_info
+   *   The entity type bundle info.
    * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
    *   The language manager.
    */
-  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings, EntityTypeManagerInterface $entity_type_manager, LanguageManagerInterface $language_manager) {
-    parent::__construct($plugin_id, $plugin_definition, $field_definition, $settings, $label, $view_mode, $third_party_settings, $entity_type_manager);
+  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings, EntityTypeManagerInterface $entity_type_manager, EntityTypeBundleInfoInterface $entity_type_bundle_info, LanguageManagerInterface $language_manager) {
+    parent::__construct($plugin_id, $plugin_definition, $field_definition, $settings, $label, $view_mode, $third_party_settings, $entity_type_manager, $entity_type_bundle_info);
 
     $this->languageManager = $language_manager;
   }
@@ -71,6 +74,7 @@ public static function create(ContainerInterface $container, array $configuratio
       $configuration['view_mode'],
       $configuration['third_party_settings'],
       $container->get('entity_type.manager'),
+      $container->get('entity_type.bundle.info'),
       $container->get('language_manager')
     );
   }
diff --git a/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/StringFormatter.php b/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/StringFormatter.php
index 96f1895840..bef15305ba 100644
--- a/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/StringFormatter.php
+++ b/core/lib/Drupal/Core/Field/Plugin/Field/FieldFormatter/StringFormatter.php
@@ -10,6 +10,7 @@
 use Drupal\Core\Field\FieldItemListInterface;
 use Drupal\Core\Form\FormStateInterface;
 use Symfony\Component\DependencyInjection\ContainerInterface;
+use Drupal\Core\Entity\EntityTypeBundleInfoInterface;
 
 /**
  * Plugin implementation of the 'string' formatter.
@@ -35,6 +36,13 @@ class StringFormatter extends FormatterBase {
    */
   protected $entityTypeManager;
 
+  /**
+   * The entity type bundle info.
+   *
+   * @var \Drupal\Core\Entity\EntityTypeBundleInfoInterface
+   */
+  protected $entityTypeBundleInfo;
+
   /**
    * Constructs a StringFormatter instance.
    *
@@ -54,11 +62,14 @@ class StringFormatter extends FormatterBase {
    *   Any third party settings settings.
    * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
    *   The entity type manager.
+   * @param \Drupal\Core\Entity\EntityTypeBundleInfoInterface $entity_type_bundle_info
+   *   The entity type bundle info.
    */
-  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings, EntityTypeManagerInterface $entity_type_manager) {
+  public function __construct($plugin_id, $plugin_definition, FieldDefinitionInterface $field_definition, array $settings, $label, $view_mode, array $third_party_settings, EntityTypeManagerInterface $entity_type_manager, EntityTypeBundleInfoInterface $entity_type_bundle_info) {
     parent::__construct($plugin_id, $plugin_definition, $field_definition, $settings, $label, $view_mode, $third_party_settings);
 
     $this->entityTypeManager = $entity_type_manager;
+    $this->entityTypeBundleInfo = $entity_type_bundle_info;
   }
 
   /**
@@ -73,7 +84,8 @@ public static function create(ContainerInterface $container, array $configuratio
       $configuration['label'],
       $configuration['view_mode'],
       $configuration['third_party_settings'],
-      $container->get('entity_type.manager')
+      $container->get('entity_type.manager'),
+      $container->get('entity_type.bundle.info')
     );
   }
 
@@ -129,7 +141,37 @@ public function viewElements(FieldItemListInterface $items, $langcode) {
     $entity_type = $entity->getEntityType();
 
     if ($this->getSetting('link_to_entity') && !$entity->isNew() && $entity_type->hasLinkTemplate('canonical')) {
-      $url = $this->getEntityUrl($entity);
+      // Check for uri_callback function.
+      $bundle = $entity->bundle();
+
+      // A bundle-specific callback takes precedence over the generic one for
+      // the entity type.
+      $bundles = $this->entityTypeBundleInfo->getBundleInfo($entity->getEntityTypeId());
+      if (isset($bundles[$bundle]['uri_callback'])) {
+        $uri_callback = $bundles[$bundle]['uri_callback'];
+      }
+      elseif ($entity_uri_callback = $entity->getEntityType()->getUriCallback()) {
+        $uri_callback = $entity_uri_callback;
+      }
+
+      // Invoke the callback to get the URI. If there is no callback, use the
+      // default URI format.
+      if (isset($uri_callback) && is_callable($uri_callback)) {
+        $url = call_user_func($uri_callback, $entity);
+
+        // Pass the entity data through as options, so that alter functions do not
+        // need to look up this entity again.
+        $url
+          ->setOption('entity_type', $entity->getEntityTypeId())
+          ->setOption('entity', $this);
+
+        // Display links by default based on the current language.
+        $url->setOption('language', $entity->language());
+      }
+      else {
+        // For the default revision this falls back to 'canonical'
+        $url = $this->getEntityUrl($entity);
+      }
     }
 
     foreach ($items as $delta => $item) {
diff --git a/core/lib/Drupal/Core/Http/KernelEvent.php b/core/lib/Drupal/Core/Http/KernelEvent.php
index 301f31aab3..5a9219c315 100644
--- a/core/lib/Drupal/Core/Http/KernelEvent.php
+++ b/core/lib/Drupal/Core/Http/KernelEvent.php
@@ -5,7 +5,7 @@
 
 namespace Drupal\Core\Http;
 
-use Drupal\Component\EventDispatcher\Event;
+use Symfony\Component\EventDispatcher\Event;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\HttpKernelInterface;
 
diff --git a/core/lib/Drupal/Core/Mail/MailManager.php b/core/lib/Drupal/Core/Mail/MailManager.php
index 05c0c8adfa..4fd4f9ba7e 100644
--- a/core/lib/Drupal/Core/Mail/MailManager.php
+++ b/core/lib/Drupal/Core/Mail/MailManager.php
@@ -5,6 +5,7 @@
 use Drupal\Component\Render\MarkupInterface;
 use Drupal\Component\Render\PlainTextOutput;
 use Drupal\Component\Utility\Html;
+use Drupal\Component\Utility\Mail as MailHelper;
 use Drupal\Core\Logger\LoggerChannelFactoryInterface;
 use Drupal\Core\Messenger\MessengerTrait;
 use Drupal\Core\Plugin\DefaultPluginManager;
@@ -16,8 +17,6 @@
 use Drupal\Core\Render\RendererInterface;
 use Drupal\Core\StringTranslation\StringTranslationTrait;
 use Drupal\Core\StringTranslation\TranslationInterface;
-use Symfony\Component\Mime\Address;
-use Symfony\Component\Mime\Header\MailboxHeader;
 
 /**
  * Provides a Mail plugin manager.
@@ -256,12 +255,9 @@ public function doMail($module, $key, $to, $langcode, $params = [], $reply = NUL
     // To prevent email from looking like spam, the addresses in the Sender and
     // Return-Path headers should have a domain authorized to use the
     // originating SMTP server.
-    $headers['From'] = $headers['Sender'] = $headers['Return-Path'] = $site_mail;
+    $headers['Sender'] = $headers['Return-Path'] = $site_mail;
     // Make sure the site-name is a RFC-2822 compliant 'display-name'.
-    if ($site_mail) {
-      $mailbox = new MailboxHeader('From', new Address($site_mail, $site_config->get('name') ?: ''));
-      $headers['From'] = $mailbox->getBodyAsString();
-    }
+    $headers['From'] = MailHelper::formatDisplayName($site_config->get('name')) . ' <' . $site_mail . '>';
     if ($reply) {
       $headers['Reply-to'] = $reply;
     }
diff --git a/core/lib/Drupal/Core/Mail/Plugin/Mail/PhpMail.php b/core/lib/Drupal/Core/Mail/Plugin/Mail/PhpMail.php
index 138257b8da..27e5c76e5d 100644
--- a/core/lib/Drupal/Core/Mail/Plugin/Mail/PhpMail.php
+++ b/core/lib/Drupal/Core/Mail/Plugin/Mail/PhpMail.php
@@ -2,11 +2,10 @@
 
 namespace Drupal\Core\Mail\Plugin\Mail;
 
+use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Mail\MailFormatHelper;
 use Drupal\Core\Mail\MailInterface;
 use Drupal\Core\Site\Settings;
-use Symfony\Component\Mime\Header\Headers;
-use Symfony\Component\Mime\Header\UnstructuredHeader;
 
 /**
  * Defines the default Drupal mail backend, using PHP's native mail() function.
@@ -19,13 +18,6 @@
  */
 class PhpMail implements MailInterface {
 
-  /**
-   * A list of headers that can contain multiple email addresses.
-   *
-   * @see \Symfony\Component\Mime\Header\Headers::HEADER_CLASS_MAP
-   */
-  private const MAILBOX_LIST_HEADERS = ['from', 'to', 'reply-to', 'cc', 'bcc'];
-
   /**
    * The configuration factory.
    *
@@ -83,17 +75,13 @@ public function mail(array $message) {
         unset($message['headers']['Return-Path']);
       }
     }
-
-    $headers = new Headers();
+    $mimeheaders = [];
     foreach ($message['headers'] as $name => $value) {
-      if (in_array(strtolower($name), self::MAILBOX_LIST_HEADERS, TRUE)) {
-        $value = explode(',', $value);
-      }
-      $headers->addHeader($name, $value);
+      $mimeheaders[] = $name . ': ' . Unicode::mimeHeaderEncode($value);
     }
     $line_endings = Settings::get('mail_line_endings', PHP_EOL);
     // Prepare mail commands.
-    $mail_subject = (new UnstructuredHeader('subject', $message['subject']))->getBodyAsString();
+    $mail_subject = Unicode::mimeHeaderEncode($message['subject']);
     // Note: email uses CRLF for line-endings. PHP's API requires LF
     // on Unix and CRLF on Windows. Drupal automatically guesses the
     // line-ending format appropriate for your system. If you need to
@@ -101,8 +89,7 @@ public function mail(array $message) {
     $mail_body = preg_replace('@\r?\n@', $line_endings, $message['body']);
     // For headers, PHP's API suggests that we use CRLF normally,
     // but some MTAs incorrectly replace LF with CRLF. See #234403.
-    $mail_headers = str_replace("\r\n", "\n", $headers->toString());
-    $mail_subject = str_replace("\r\n", "\n", $mail_subject);
+    $mail_headers = implode("\n", $mimeheaders);
 
     $request = \Drupal::request();
 
diff --git a/core/lib/Drupal/Core/Render/MainContent/DialogRenderer.php b/core/lib/Drupal/Core/Render/MainContent/DialogRenderer.php
index 77fc33557d..c445d8507c 100644
--- a/core/lib/Drupal/Core/Render/MainContent/DialogRenderer.php
+++ b/core/lib/Drupal/Core/Render/MainContent/DialogRenderer.php
@@ -61,7 +61,7 @@ public function renderResponse(array $main_content, Request $request, RouteMatch
     $title = isset($main_content['#title']) ? $main_content['#title'] : $this->titleResolver->getTitle($request, $route_match->getRouteObject());
 
     // Determine the dialog options and the target for the OpenDialogCommand.
-    $options = $request->request->all('dialogOptions');
+    $options = $request->request->get('dialogOptions', []);
     $target = $this->determineTargetSelector($options, $route_match);
 
     $response->addCommand(new OpenDialogCommand($target, $title, $content, $options));
diff --git a/core/lib/Drupal/Core/Render/MainContent/ModalRenderer.php b/core/lib/Drupal/Core/Render/MainContent/ModalRenderer.php
index 6f6d117332..d250d57329 100644
--- a/core/lib/Drupal/Core/Render/MainContent/ModalRenderer.php
+++ b/core/lib/Drupal/Core/Render/MainContent/ModalRenderer.php
@@ -31,7 +31,7 @@ public function renderResponse(array $main_content, Request $request, RouteMatch
 
     // Determine the title: use the title provided by the main content if any,
     // otherwise get it from the routing information.
-    $options = $request->request->all('dialogOptions');
+    $options = $request->request->get('dialogOptions', []);
 
     $response->addCommand(new OpenModalDialogCommand($title, $content, $options));
     return $response;
diff --git a/core/lib/Drupal/Core/Render/MainContent/OffCanvasRenderer.php b/core/lib/Drupal/Core/Render/MainContent/OffCanvasRenderer.php
index dc575a5fc2..086e84f929 100644
--- a/core/lib/Drupal/Core/Render/MainContent/OffCanvasRenderer.php
+++ b/core/lib/Drupal/Core/Render/MainContent/OffCanvasRenderer.php
@@ -64,7 +64,7 @@ public function renderResponse(array $main_content, Request $request, RouteMatch
 
     // Determine the title: use the title provided by the main content if any,
     // otherwise get it from the routing information.
-    $options = $request->request->all('dialogOptions');
+    $options = $request->request->get('dialogOptions', []);
     $response->addCommand(new OpenOffCanvasDialogCommand($title, $content, $options, NULL, $this->position));
     return $response;
   }
diff --git a/core/lib/Drupal/Core/Theme/AjaxBasePageNegotiator.php b/core/lib/Drupal/Core/Theme/AjaxBasePageNegotiator.php
index 1c19472df8..5cd2ee3057 100644
--- a/core/lib/Drupal/Core/Theme/AjaxBasePageNegotiator.php
+++ b/core/lib/Drupal/Core/Theme/AjaxBasePageNegotiator.php
@@ -65,7 +65,7 @@ public function __construct(CsrfTokenGenerator $token_generator, ConfigFactoryIn
    * {@inheritdoc}
    */
   public function applies(RouteMatchInterface $route_match) {
-    $ajax_page_state = $this->requestStack->getCurrentRequest()->request->all('ajax_page_state');
+    $ajax_page_state = $this->requestStack->getCurrentRequest()->request->get('ajax_page_state');
     return !empty($ajax_page_state['theme']) && isset($ajax_page_state['theme_token']);
   }
 
@@ -73,7 +73,7 @@ public function applies(RouteMatchInterface $route_match) {
    * {@inheritdoc}
    */
   public function determineActiveTheme(RouteMatchInterface $route_match) {
-    $ajax_page_state = $this->requestStack->getCurrentRequest()->request->all('ajax_page_state');
+    $ajax_page_state = $this->requestStack->getCurrentRequest()->request->get('ajax_page_state');
     $theme = $ajax_page_state['theme'];
     $token = $ajax_page_state['theme_token'];
 
diff --git a/core/misc/cspell/dictionary.txt b/core/misc/cspell/dictionary.txt
index c9966e95a9..9e4aa28199 100644
--- a/core/misc/cspell/dictionary.txt
+++ b/core/misc/cspell/dictionary.txt
@@ -907,6 +907,7 @@ middlewares
 midgardmvc
 mikey
 milli
+mimeheaders
 mimetypes
 minifyzombies
 minimatch
diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 9ad36259a3..e551a4eb05 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -12,6 +12,7 @@
 
 use Drupal\comment\CommentInterface;
 use Drupal\comment\Entity\CommentType;
+use Drupal\Component\Utility\Unicode;
 use Drupal\Core\Entity\FieldableEntityInterface;
 use Drupal\comment\Plugin\Field\FieldType\CommentItemInterface;
 use Drupal\Core\Entity\Entity\EntityViewMode;
@@ -72,13 +73,13 @@ function comment_help($route_name, RouteMatchInterface $route_match) {
  * Entity URI callback.
  */
 function comment_uri(CommentInterface $comment) {
-  return new Url(
-    'entity.comment.canonical',
-    [
-      'comment' => $comment->id(),
-    ],
-    ['fragment' => 'comment-' . $comment->id()]
-  );
+  $comment_permalink = $comment->permalink();
+  if ($comment->hasField('comment_body') && ($body = $comment->get('comment_body')->value)) {
+    $attributes = $comment_permalink->getOption('attributes') ?: [];
+    $attributes += ['title' => Unicode::truncate($body, 128)];
+    $comment_permalink->setOption('attributes', $attributes);
+  }
+  return $comment_permalink;
 }
 
 /**
diff --git a/core/modules/comment/src/Controller/CommentController.php b/core/modules/comment/src/Controller/CommentController.php
index ee4368b0d4..2cba4ac918 100644
--- a/core/modules/comment/src/Controller/CommentController.php
+++ b/core/modules/comment/src/Controller/CommentController.php
@@ -337,11 +337,11 @@ public function renderNewCommentsNodeLinks(Request $request) {
       throw new AccessDeniedHttpException();
     }
 
-    if (!$request->request->has('node_ids') || !$request->request->has('field_name')) {
+    $nids = $request->request->get('node_ids');
+    $field_name = $request->request->get('field_name');
+    if (!isset($nids)) {
       throw new NotFoundHttpException();
     }
-    $nids = $request->request->all('node_ids');
-    $field_name = $request->request->get('field_name');
     // Only handle up to 100 nodes.
     $nids = array_slice($nids, 0, 100);
 
diff --git a/core/modules/comment/tests/src/Functional/CommentBlockTest.php b/core/modules/comment/tests/src/Functional/CommentBlockTest.php
index 29ebe8f9c8..bd3b54481c 100644
--- a/core/modules/comment/tests/src/Functional/CommentBlockTest.php
+++ b/core/modules/comment/tests/src/Functional/CommentBlockTest.php
@@ -73,6 +73,7 @@ public function testRecentCommentBlock() {
     $this->assertNoText($comments[10]->getSubject());
     for ($i = 0; $i < 10; $i++) {
       $this->assertSession()->pageTextContains($comments[$i]->getSubject());
+      $this->assertSession()->linkByHrefExists($comments[$i]->permalink()->toString());
       if ($i > 1) {
         $previous_position = $position;
         $position = strpos($this->getSession()->getPage()->getContent(), $comments[$i]->getSubject());
diff --git a/core/modules/contextual/src/ContextualController.php b/core/modules/contextual/src/ContextualController.php
index 378b5236c4..cd6ddb40a8 100644
--- a/core/modules/contextual/src/ContextualController.php
+++ b/core/modules/contextual/src/ContextualController.php
@@ -60,15 +60,15 @@ public static function create(ContainerInterface $container) {
    * @see contextual_preprocess()
    */
   public function render(Request $request) {
-    if (!$request->request->has('ids')) {
+    $ids = $request->request->get('ids');
+    if (!isset($ids)) {
       throw new BadRequestHttpException('No contextual ids specified.');
     }
-    $ids = $request->request->all('ids');
 
-    if (!$request->request->has('tokens')) {
+    $tokens = $request->request->get('tokens');
+    if (!isset($tokens)) {
       throw new BadRequestHttpException('No contextual ID tokens specified.');
     }
-    $tokens = $request->request->all('tokens');
 
     $rendered = [];
     foreach ($ids as $key => $id) {
diff --git a/core/modules/field_ui/src/Form/FieldConfigEditForm.php b/core/modules/field_ui/src/Form/FieldConfigEditForm.php
index 7503568129..db8122c4d9 100644
--- a/core/modules/field_ui/src/Form/FieldConfigEditForm.php
+++ b/core/modules/field_ui/src/Form/FieldConfigEditForm.php
@@ -206,7 +206,7 @@ public function save(array $form, FormStateInterface $form_state) {
     $this->messenger()->addStatus($this->t('Saved %label configuration.', ['%label' => $this->entity->getLabel()]));
 
     $request = $this->getRequest();
-    if (($destinations = $request->query->all('destinations')) && $next_destination = FieldUI::getNextDestination($destinations)) {
+    if (($destinations = $request->query->get('destinations')) && $next_destination = FieldUI::getNextDestination($destinations)) {
       $request->query->remove('destinations');
       $form_state->setRedirectUrl($next_destination);
     }
diff --git a/core/modules/field_ui/src/Form/FieldStorageConfigEditForm.php b/core/modules/field_ui/src/Form/FieldStorageConfigEditForm.php
index a8ea75d598..bf1994c1f9 100644
--- a/core/modules/field_ui/src/Form/FieldStorageConfigEditForm.php
+++ b/core/modules/field_ui/src/Form/FieldStorageConfigEditForm.php
@@ -229,7 +229,7 @@ public function save(array $form, FormStateInterface $form_state) {
       $this->entity->save();
       $this->messenger()->addStatus($this->t('Updated field %label field settings.', ['%label' => $field_label]));
       $request = $this->getRequest();
-      if (($destinations = $request->query->all('destinations')) && $next_destination = FieldUI::getNextDestination($destinations)) {
+      if (($destinations = $request->query->get('destinations')) && $next_destination = FieldUI::getNextDestination($destinations)) {
         $request->query->remove('destinations');
         $form_state->setRedirectUrl($next_destination);
       }
diff --git a/core/modules/history/src/Controller/HistoryController.php b/core/modules/history/src/Controller/HistoryController.php
index ca3498ead8..c6a4834903 100644
--- a/core/modules/history/src/Controller/HistoryController.php
+++ b/core/modules/history/src/Controller/HistoryController.php
@@ -28,10 +28,10 @@ public function getNodeReadTimestamps(Request $request) {
       throw new AccessDeniedHttpException();
     }
 
-    if (!$request->request->has('node_ids')) {
+    $nids = $request->request->get('node_ids');
+    if (!isset($nids)) {
       throw new NotFoundHttpException();
     }
-    $nids = $request->request->all('node_ids');
     return new JsonResponse(history_read_multiple($nids));
   }
 
diff --git a/core/modules/jsonapi/src/Controller/EntityResource.php b/core/modules/jsonapi/src/Controller/EntityResource.php
index b4124dd4d7..47bc9c056d 100644
--- a/core/modules/jsonapi/src/Controller/EntityResource.php
+++ b/core/modules/jsonapi/src/Controller/EntityResource.php
@@ -1217,13 +1217,13 @@ protected function entityExists(EntityInterface $entity) {
    */
   protected function getJsonApiParams(Request $request, ResourceType $resource_type) {
     if ($request->query->has('filter')) {
-      $params[Filter::KEY_NAME] = Filter::createFromQueryParameter($request->query->all('filter'), $resource_type, $this->fieldResolver);
+      $params[Filter::KEY_NAME] = Filter::createFromQueryParameter($request->query->get('filter'), $resource_type, $this->fieldResolver);
     }
     if ($request->query->has('sort')) {
-      $params[Sort::KEY_NAME] = Sort::createFromQueryParameter($request->query->all()['sort'] ?? NULL);
+      $params[Sort::KEY_NAME] = Sort::createFromQueryParameter($request->query->get('sort'));
     }
     if ($request->query->has('page')) {
-      $params[OffsetPage::KEY_NAME] = OffsetPage::createFromQueryParameter($request->query->all('page'));
+      $params[OffsetPage::KEY_NAME] = OffsetPage::createFromQueryParameter($request->query->get('page'));
     }
     else {
       $params[OffsetPage::KEY_NAME] = OffsetPage::createFromQueryParameter(['page' => ['offset' => OffsetPage::DEFAULT_OFFSET, 'limit' => OffsetPage::SIZE_MAX]]);
diff --git a/core/modules/jsonapi/src/EventSubscriber/ResourceResponseSubscriber.php b/core/modules/jsonapi/src/EventSubscriber/ResourceResponseSubscriber.php
index 7a065bfd83..edf81cb677 100644
--- a/core/modules/jsonapi/src/EventSubscriber/ResourceResponseSubscriber.php
+++ b/core/modules/jsonapi/src/EventSubscriber/ResourceResponseSubscriber.php
@@ -146,10 +146,10 @@ protected static function generateContext(Request $request) {
       'account' => NULL,
       'sparse_fieldset' => NULL,
     ];
-    if ($request->query->has('fields')) {
+    if ($request->query->get('fields')) {
       $context['sparse_fieldset'] = array_map(function ($item) {
         return explode(',', $item);
-      }, $request->query->all('fields'));
+      }, $request->query->get('fields'));
     }
     return $context;
   }
diff --git a/core/modules/jsonapi/tests/src/Kernel/Controller/EntityResourceTest.php b/core/modules/jsonapi/tests/src/Kernel/Controller/EntityResourceTest.php
index 0cae3b71de..5f0246f2cb 100644
--- a/core/modules/jsonapi/tests/src/Kernel/Controller/EntityResourceTest.php
+++ b/core/modules/jsonapi/tests/src/Kernel/Controller/EntityResourceTest.php
@@ -3,7 +3,6 @@
 namespace Drupal\Tests\jsonapi\Kernel\Controller;
 
 use Drupal\Core\Field\FieldStorageDefinitionInterface;
-use Drupal\Core\Http\InputBag;
 use Drupal\jsonapi\CacheableResourceResponse;
 use Drupal\jsonapi\ResourceType\ResourceType;
 use Drupal\jsonapi\JsonApiResource\Data;
@@ -14,6 +13,7 @@
 use Drupal\user\Entity\Role;
 use Drupal\user\Entity\User;
 use Drupal\user\RoleInterface;
+use Symfony\Component\HttpFoundation\ParameterBag;
 use Symfony\Component\HttpFoundation\Request;
 
 /**
@@ -186,7 +186,7 @@ protected function createEntityResource() {
    */
   public function testGetPagedCollection() {
     $request = Request::create('/jsonapi/node/article');
-    $request->query = new InputBag([
+    $request->query = new ParameterBag([
       'sort' => 'nid',
       'page' => [
         'offset' => 1,
@@ -215,7 +215,7 @@ public function testGetPagedCollection() {
    */
   public function testGetEmptyCollection() {
     $request = Request::create('/jsonapi/node/article');
-    $request->query = new InputBag(['filter' => ['id' => 'invalid']]);
+    $request->query = new ParameterBag(['filter' => ['id' => 'invalid']]);
 
     // Get the response.
     $resource_type = new ResourceType('node', 'article', NULL);
diff --git a/core/modules/media_library/src/MediaLibraryState.php b/core/modules/media_library/src/MediaLibraryState.php
index 63e29e09ac..e1fd6e2e8b 100644
--- a/core/modules/media_library/src/MediaLibraryState.php
+++ b/core/modules/media_library/src/MediaLibraryState.php
@@ -3,9 +3,7 @@
 namespace Drupal\media_library;
 
 use Drupal\Component\Utility\Crypt;
-use Drupal\Core\Http\InputBag;
 use Drupal\Core\Site\Settings;
-use Symfony\Component\HttpFoundation\InputBag as SymfonyInputBag;
 use Symfony\Component\HttpFoundation\ParameterBag;
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\Exception\BadRequestHttpException;
@@ -96,20 +94,15 @@ public static function create($opener_id, array $allowed_media_type_ids, $select
    */
   public static function fromRequest(Request $request) {
     $query = $request->query;
-    // Replace ParameterBag with InputBag for compatibility with Symfony 5.
-    // @todo Remove this when Symfony 4 is no longer supported.
-    if (!($query instanceof InputBag || $query instanceof SymfonyInputBag)) {
-      $query = new InputBag($query->all());
-    }
 
     // Create a MediaLibraryState object through the create method to make sure
     // all validation runs.
     $state = static::create(
       $query->get('media_library_opener_id'),
-      $query->all('media_library_allowed_types'),
+      $query->get('media_library_allowed_types', []),
       $query->get('media_library_selected_type'),
       $query->get('media_library_remaining'),
-      $query->all('media_library_opener_parameters')
+      $query->get('media_library_opener_parameters', [])
     );
 
     // The request parameters need to contain a valid hash to prevent a
@@ -229,7 +222,7 @@ public function getOpenerId() {
    *   The media type IDs.
    */
   public function getAllowedTypeIds() {
-    return $this->all('media_library_allowed_types');
+    return $this->get('media_library_allowed_types');
   }
 
   /**
@@ -273,29 +266,7 @@ public function getAvailableSlots() {
    *   An associative array of all opener-specific parameter values.
    */
   public function getOpenerParameters() {
-    return $this->all('media_library_opener_parameters');
-  }
-
-  /**
-   * Returns the parameters.
-   *
-   * @param string|null $key
-   *   The name of the parameter to return or null to get them all.
-   *
-   * @return array
-   *   An array of parameters.
-   */
-  public function all(string $key = NULL): array {
-    if ($key === NULL) {
-      return $this->parameters;
-    }
-
-    $value = $this->parameters[$key] ?? [];
-    if (!is_array($value)) {
-      throw new \UnexpectedValueException(sprintf('Unexpected value for parameter "%s": expecting "array", got "%s".', $key, get_debug_type($value)));
-    }
-
-    return $value;
+    return $this->get('media_library_opener_parameters', []);
   }
 
 }
diff --git a/core/modules/menu_ui/src/Controller/MenuController.php b/core/modules/menu_ui/src/Controller/MenuController.php
index e76ff6c560..7958c101ac 100644
--- a/core/modules/menu_ui/src/Controller/MenuController.php
+++ b/core/modules/menu_ui/src/Controller/MenuController.php
@@ -50,7 +50,7 @@ public static function create(ContainerInterface $container) {
    */
   public function getParentOptions(Request $request) {
     $available_menus = [];
-    if ($menus = $request->request->all('menus')) {
+    if ($menus = $request->request->get('menus')) {
       foreach ($menus as $menu) {
         $available_menus[$menu] = $menu;
       }
diff --git a/core/modules/quickedit/src/QuickEditController.php b/core/modules/quickedit/src/QuickEditController.php
index d5967090b0..bc81769cdb 100644
--- a/core/modules/quickedit/src/QuickEditController.php
+++ b/core/modules/quickedit/src/QuickEditController.php
@@ -116,11 +116,11 @@ public static function create(ContainerInterface $container) {
    *   The JSON response.
    */
   public function metadata(Request $request) {
-    if (!$request->request->has('fields')) {
+    $fields = $request->request->get('fields');
+    if (!isset($fields)) {
       throw new NotFoundHttpException();
     }
-    $fields = $request->request->all('fields');
-    $entities = $request->request->all('entities');
+    $entities = $request->request->get('entities');
 
     $metadata = [];
     foreach ($fields as $field) {
@@ -147,7 +147,7 @@ public function metadata(Request $request) {
 
       // If the entity information for this field is requested, include it.
       $entity_id = $entity->getEntityTypeId() . '/' . $entity_id;
-      if (in_array($entity_id, $entities, TRUE) && !isset($metadata[$entity_id])) {
+      if (is_array($entities) && in_array($entity_id, $entities) && !isset($metadata[$entity_id])) {
         $metadata[$entity_id] = $this->metadataGenerator->generateEntityMetadata($entity);
       }
 
@@ -168,10 +168,10 @@ public function metadata(Request $request) {
    */
   public function attachments(Request $request) {
     $response = new AjaxResponse();
-    if (!$request->request->has('editors')) {
+    $editors = $request->request->get('editors');
+    if (!isset($editors)) {
       throw new NotFoundHttpException();
     }
-    $editors = $request->request->all('editors');
 
     $response->setAttachments($this->editorSelector->getEditorAttachments($editors));
 
@@ -229,7 +229,7 @@ public function fieldForm(EntityInterface $entity, $field_name, $langcode, $view
 
       // Re-render the updated field for other view modes (i.e. for other
       // instances of the same logical field on the user's page).
-      $other_view_mode_ids = $request->request->all('other_view_modes');
+      $other_view_mode_ids = $request->request->get('other_view_modes') ?: [];
       $other_view_modes = array_map($render_field_in_view_mode, array_combine($other_view_mode_ids, $other_view_mode_ids));
 
       $response->addCommand(new FieldFormSavedCommand($output, $other_view_modes));
diff --git a/core/modules/system/tests/modules/dialog_renderer_test/src/Render/MainContent/WideModalRenderer.php b/core/modules/system/tests/modules/dialog_renderer_test/src/Render/MainContent/WideModalRenderer.php
index feb5ca7ead..aecb4dd0de 100644
--- a/core/modules/system/tests/modules/dialog_renderer_test/src/Render/MainContent/WideModalRenderer.php
+++ b/core/modules/system/tests/modules/dialog_renderer_test/src/Render/MainContent/WideModalRenderer.php
@@ -60,7 +60,7 @@ public function renderResponse(array $main_content, Request $request, RouteMatch
 
     // Determine the title: use the title provided by the main content if any,
     // otherwise get it from the routing information.
-    $options = $request->request->all('dialogOptions');
+    $options = $request->request->get('dialogOptions', []);
     // Override width option.
     switch ($this->mode) {
       case 'wide':
diff --git a/core/modules/system/tests/src/Kernel/Mail/MailTest.php b/core/modules/system/tests/src/Kernel/Mail/MailTest.php
index c6c2545694..9582084a03 100644
--- a/core/modules/system/tests/src/Kernel/Mail/MailTest.php
+++ b/core/modules/system/tests/src/Kernel/Mail/MailTest.php
@@ -3,6 +3,7 @@
 namespace Drupal\Tests\system\Kernel\Mail;
 
 use Drupal\Component\Utility\Random;
+use Drupal\Component\Utility\Unicode;
 use Drupal\Core\File\FileSystemInterface;
 use Drupal\Core\Mail\MailFormatHelper;
 use Drupal\Core\Mail\Plugin\Mail\TestMailCollector;
@@ -146,9 +147,9 @@ public function testFromAndReplyToHeader() {
     $captured_emails = \Drupal::state()->get('system.test_mail_collector');
     $sent_message = end($captured_emails);
     // From header is correctly encoded.
-    $this->assertEquals('=?utf-8?Q?Dr=C3=A9pal?= this is a very long test sentence to test what happens with very long site names <mailtest@example.com>', $sent_message['headers']['From']);
+    $this->assertEquals('=?UTF-8?B?RHLDqXBhbCB0aGlzIGlzIGEgdmVyeSBsb25nIHRlc3Qgc2VudGVuY2UgdG8gdGU=?= <mailtest@example.com>', $sent_message['headers']['From']);
     // From header is correctly encoded.
-    $this->assertEquals('Drépal this is a very long test sentence to test what happens with very long site names <mailtest@example.com>', iconv_mime_decode($sent_message['headers']['From']));
+    $this->assertEquals('Drépal this is a very long test sentence to te <mailtest@example.com>', Unicode::mimeHeaderDecode($sent_message['headers']['From']));
     $this->assertFalse(isset($sent_message['headers']['Reply-to']), 'Message reply-to is not set if not specified.');
     // Errors-to header must not be set, it is deprecated.
     $this->assertFalse(isset($sent_message['headers']['Errors-To']));
@@ -178,9 +179,9 @@ public function testFromAndReplyToHeader() {
     $captured_emails = \Drupal::state()->get('system.test_mail_collector');
     $sent_message = end($captured_emails);
     // From header is correctly encoded.
-    $this->assertEquals('=?utf-8?Q?Dr=C3=A9pal=2C_=22si=5Cte=22?= <mailtest@example.com>', $sent_message['headers']['From']);
+    $this->assertEquals('=?UTF-8?B?RHLDqXBhbCwgInNpXHRlIg==?= <mailtest@example.com>', $sent_message['headers']['From']);
     // From header is correctly encoded.
-    $this->assertEquals($site_name . ' <mailtest@example.com>', iconv_mime_decode($sent_message['headers']['From']));
+    $this->assertEquals($site_name . ' <mailtest@example.com>', Unicode::mimeHeaderDecode($sent_message['headers']['From']));
   }
 
   /**
diff --git a/core/modules/views/src/Plugin/views/argument_default/QueryParameter.php b/core/modules/views/src/Plugin/views/argument_default/QueryParameter.php
index bb21c6baa4..1b45615fd8 100644
--- a/core/modules/views/src/Plugin/views/argument_default/QueryParameter.php
+++ b/core/modules/views/src/Plugin/views/argument_default/QueryParameter.php
@@ -66,7 +66,7 @@ public function getArgument() {
     $current_request = $this->view->getRequest();
 
     if ($current_request->query->has($this->options['query_param'])) {
-      $param = $current_request->query->all()[$this->options['query_param']] ?? NULL;
+      $param = $current_request->query->get($this->options['query_param']);
       if (is_array($param)) {
         $conjunction = ($this->options['multiple'] == 'and') ? ',' : '+';
         $param = implode($conjunction, $param);
diff --git a/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php b/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php
index 468069f8d8..8e87252b93 100644
--- a/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php
+++ b/core/tests/Drupal/BuildTests/Composer/Template/ComposerProjectTemplatesTest.php
@@ -32,7 +32,7 @@ class ComposerProjectTemplatesTest extends BuildTestBase {
    *
    * @see https://getcomposer.org/doc/04-schema.md#minimum-stability
    */
-  protected const MINIMUM_STABILITY = 'RC';
+  protected const MINIMUM_STABILITY = 'stable';
 
   /**
    * The order of stability strings from least stable to most stable.
diff --git a/core/tests/Drupal/BuildTests/Framework/BuildTestBase.php b/core/tests/Drupal/BuildTests/Framework/BuildTestBase.php
index 05cb76783b..78beb2bf64 100644
--- a/core/tests/Drupal/BuildTests/Framework/BuildTestBase.php
+++ b/core/tests/Drupal/BuildTests/Framework/BuildTestBase.php
@@ -426,14 +426,13 @@ protected function instantiateServer($port, $working_dir = NULL) {
       ->start();
     // Wait until the web server has started. It is started if the port is no
     // longer available.
-    for ($i = 0; $i < 50; $i++) {
-      usleep(100000);
+    for ($i = 0; $i < 1000; $i++) {
       if (!$this->checkPortIsAvailable($port)) {
         return $ps;
       }
+      usleep(1000);
     }
-
-    throw new \RuntimeException(sprintf("Unable to start the web server.\nCMD: %s \nCODE: %d\nSTATUS: %s\nOUTPUT:\n%s\n\nERROR OUTPUT:\n%s", $ps->getCommandLine(), $ps->getExitCode(), $ps->getStatus(), $ps->getOutput(), $ps->getErrorOutput()));
+    throw new \RuntimeException(sprintf("Unable to start the web server.\nERROR OUTPUT:\n%s", $ps->getErrorOutput()));
   }
 
   /**
diff --git a/core/tests/Drupal/Tests/Component/Utility/MailTest.php b/core/tests/Drupal/Tests/Component/Utility/MailTest.php
index 3c49979f6e..5f30328919 100644
--- a/core/tests/Drupal/Tests/Component/Utility/MailTest.php
+++ b/core/tests/Drupal/Tests/Component/Utility/MailTest.php
@@ -4,18 +4,15 @@
 
 use Drupal\Component\Utility\Mail;
 use PHPUnit\Framework\TestCase;
-use Symfony\Bridge\PhpUnit\ExpectDeprecationTrait;
 
 /**
  * Test mail helpers implemented in Mail component.
  *
  * @group Utility
- * @group legacy
  *
  * @coversDefaultClass \Drupal\Component\Utility\Mail
  */
 class MailTest extends TestCase {
-  use ExpectDeprecationTrait;
 
   /**
    * Tests RFC-2822 'display-name' formatter.
@@ -24,7 +21,6 @@ class MailTest extends TestCase {
    * @covers ::formatDisplayName
    */
   public function testFormatDisplayName($string, $safe_display_name) {
-    $this->expectDeprecation('\Drupal\Component\Utility\Unicode::mimeHeaderEncode() is deprecated in drupal:9.2.0 and is removed from drupal:10.0.0. Use \Symfony\Component\Mime\Header\UnstructuredHeader instead. See https://www.drupal.org/node/3207439');
     $this->assertEquals($safe_display_name, Mail::formatDisplayName($string));
   }
 
diff --git a/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php b/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php
index 5315b0ed28..714078241a 100644
--- a/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php
+++ b/core/tests/Drupal/Tests/Component/Utility/UnicodeTest.php
@@ -4,7 +4,6 @@
 
 use Drupal\Component\Utility\Unicode;
 use PHPUnit\Framework\TestCase;
-use Symfony\Bridge\PhpUnit\ExpectDeprecationTrait;
 
 /**
  * Test unicode handling features implemented in Unicode component.
@@ -14,17 +13,14 @@
  * @coversDefaultClass \Drupal\Component\Utility\Unicode
  */
 class UnicodeTest extends TestCase {
-  use ExpectDeprecationTrait;
 
   /**
    * Tests multibyte encoding.
    *
    * @dataProvider providerTestMimeHeader
    * @covers ::mimeHeaderEncode
-   * @group legacy
    */
   public function testMimeHeaderEncode($value, $encoded) {
-    $this->expectDeprecation('\Drupal\Component\Utility\Unicode::mimeHeaderEncode() is deprecated in drupal:9.2.0 and is removed from drupal:10.0.0. Use \Symfony\Component\Mime\Header\UnstructuredHeader instead. See https://www.drupal.org/node/3207439');
     $this->assertEquals($encoded, Unicode::mimeHeaderEncode($value));
   }
 
@@ -48,10 +44,8 @@ public function providerTestMimeHeader() {
    *
    * @dataProvider providerTestMimeHeaderDecode
    * @covers ::mimeHeaderDecode
-   * @group legacy
    */
   public function testMimeHeaderDecode($value, $encoded) {
-    $this->expectDeprecation('\Drupal\Component\Utility\Unicode::mimeHeaderDecode() is deprecated in drupal:9.2.0 and is removed from drupal:10.0.0. Use iconv_mime_decode() instead. See https://www.drupal.org/node/3207439');
     $this->assertEquals($value, Unicode::mimeHeaderDecode($encoded));
   }
 
diff --git a/core/tests/Drupal/Tests/Core/Theme/AjaxBasePageNegotiatorTest.php b/core/tests/Drupal/Tests/Core/Theme/AjaxBasePageNegotiatorTest.php
index 62fbcd5a71..cb65353201 100644
--- a/core/tests/Drupal/Tests/Core/Theme/AjaxBasePageNegotiatorTest.php
+++ b/core/tests/Drupal/Tests/Core/Theme/AjaxBasePageNegotiatorTest.php
@@ -3,7 +3,6 @@
 namespace Drupal\Tests\Core\Theme;
 
 use Drupal\Core\Access\CsrfTokenGenerator;
-use Drupal\Core\Http\InputBag;
 use Drupal\Core\Routing\RouteMatch;
 use Drupal\Core\Theme\AjaxBasePageNegotiator;
 use Drupal\Tests\UnitTestCase;
@@ -56,7 +55,6 @@ public function setUp(): void {
    */
   public function testApplies($request_data, $expected) {
     $request = new Request([], $request_data);
-    $request->request = new InputBag($request->request->all());
     $route_match = RouteMatch::createFromRequest($request);
     $this->requestStack->push($request);
 
@@ -81,7 +79,6 @@ public function testDetermineActiveThemeValidToken() {
     $theme_token = 'valid_theme_token';
 
     $request = new Request([], ['ajax_page_state' => ['theme' => $theme, 'theme_token' => $theme_token]]);
-    $request->request = new InputBag($request->request->all());
     $this->requestStack->push($request);
     $route_match = RouteMatch::createFromRequest($request);
 
@@ -99,7 +96,6 @@ public function testDetermineActiveThemeInvalidToken() {
     $theme_token = 'invalid_theme_token';
 
     $request = new Request([], ['ajax_page_state' => ['theme' => $theme, 'theme_token' => $theme_token]]);
-    $request->request = new InputBag($request->request->all());
     $this->requestStack->push($request);
     $route_match = RouteMatch::createFromRequest($request);
 
@@ -119,7 +115,6 @@ public function testDetermineActiveThemeDefaultTheme() {
     $theme_token = '';
 
     $request = new Request([], ['ajax_page_state' => ['theme' => $theme, 'theme_token' => $theme_token]]);
-    $request->request = new InputBag($request->request->all());
     $this->requestStack->push($request);
     $route_match = RouteMatch::createFromRequest($request);