--- /dev/null
+<?php
+
+namespace Drupal\FunctionalTests\Routing;
+
+use Drupal\field\Entity\FieldConfig;
+use Drupal\field\Entity\FieldStorageConfig;
+use Drupal\language\Entity\ConfigurableLanguage;
+use Drupal\link\LinkItemInterface;
+use Drupal\Tests\BrowserTestBase;
+
+/**
+ * Tests that route lookup is cached by the current language.
+ *
+ * @group routing
+ */
+class RouteCachingLanguageTest extends BrowserTestBase {
+
+ /**
+ * Modules to enable.
+ *
+ * @var array
+ */
+ public static $modules = ['path', 'node', 'content_translation', 'link', 'block'];
+
+ /**
+ * An user with permissions to administer content types.
+ *
+ * @var \Drupal\user\UserInterface
+ */
+ protected $webUser;
+
+ protected function setUp() {
+ parent::setUp();
+
+ $this->createContentType(['type' => 'page']);
+
+ $this->drupalPlaceBlock('local_tasks_block');
+ $this->drupalPlaceBlock('page_title_block');
+
+ $permissions = [
+ 'access administration pages',
+ 'administer content translation',
+ 'administer content types',
+ 'administer languages',
+ 'administer url aliases',
+ 'create content translations',
+ 'create page content',
+ 'create url aliases',
+ 'edit any page content',
+ 'translate any entity',
+ ];
+ // Create and log in user.
+ $this->webUser = $this->drupalCreateUser($permissions);
+ $this->drupalLogin($this->webUser);
+
+ // Enable French language.
+ ConfigurableLanguage::createFromLangcode('fr')->save();
+
+ // Enable translation for page node.
+ $edit = [
+ 'entity_types[node]' => 1,
+ 'settings[node][page][translatable]' => 1,
+ 'settings[node][page][fields][path]' => 1,
+ 'settings[node][page][fields][body]' => 1,
+ 'settings[node][page][settings][language][language_alterable]' => 1,
+ ];
+ $this->drupalPostForm('admin/config/regional/content-language', $edit, t('Save configuration'));
+
+ // Create a field with settings to validate.
+ $field_storage = FieldStorageConfig::create([
+ 'field_name' => 'field_link',
+ 'entity_type' => 'node',
+ 'type' => 'link',
+ ]);
+ $field_storage->save();
+ $field = FieldConfig::create([
+ 'field_storage' => $field_storage,
+ 'bundle' => 'page',
+ 'settings' => [
+ 'title' => DRUPAL_OPTIONAL,
+ 'link_type' => LinkItemInterface::LINK_GENERIC,
+ ],
+ ]);
+ $field->save();
+
+ entity_get_form_display('node', 'page', 'default')
+ ->setComponent('field_link', [
+ 'type' => 'link_default',
+ ])
+ ->save();
+ entity_get_display('node', 'page', 'full')
+ ->setComponent('field_link', [
+ 'type' => 'link',
+ ])
+ ->save();
+
+ // Enable URL language detection and selection and set a prefix for both
+ // languages.
+ $edit = ['language_interface[enabled][language-url]' => 1];
+ $this->drupalPostForm('admin/config/regional/language/detection', $edit, 'Save settings');
+ $edit = ['prefix[en]' => 'en'];
+ $this->drupalPostForm('admin/config/regional/language/detection/url', $edit, 'Save configuration');
+
+ // Reset the cache after changing the negotiation settings as that changes
+ // how links are built.
+ $this->resetAll();
+
+ $definitions = \Drupal::service('entity_field.manager')->getFieldDefinitions('node', 'page');
+ $this->assertTrue($definitions['path']->isTranslatable(), 'Node path is translatable.');
+ $this->assertTrue($definitions['body']->isTranslatable(), 'Node body is translatable.');
+ }
+
+ /**
+ * Creates content with a link field pointing to an alias of another language.
+ *
+ * @dataProvider providerLanguage
+ */
+ public function testLinkTranslationWithAlias($source_langcode) {
+ $source_url_options = [
+ 'language' => ConfigurableLanguage::load($source_langcode),
+ ];
+
+ // Create a target node in the source language that is the link target.
+ $edit = [
+ 'langcode[0][value]' => $source_langcode,
+ 'title[0][value]' => 'Target page',
+ 'path[0][alias]' => '/target-page',
+ ];
+ $this->drupalPostForm('node/add/page', $edit, t('Save'), $source_url_options);
+
+ // Confirm that the alias works.
+ $assert_session = $this->assertSession();
+ $assert_session->addressEquals($source_langcode . '/target-page');
+ $assert_session->statusCodeEquals(200);
+ $assert_session->pageTextContains('Target page');
+
+ // Create a second node that links to the first through the link field.
+ $edit = [
+ 'langcode[0][value]' => $source_langcode,
+ 'title[0][value]' => 'Link page',
+ 'field_link[0][uri]' => '/target-page',
+ 'field_link[0][title]' => 'Target page',
+ 'path[0][alias]' => '/link-page',
+ ];
+ $this->drupalPostForm('node/add/page', $edit, t('Save'), $source_url_options);
+
+ // Make sure the link node is displayed with a working link.
+ $assert_session->pageTextContains('Link page');
+ $this->clickLink('Target page');
+ $assert_session->addressEquals($source_langcode . '/target-page');
+ $assert_session->statusCodeEquals(200);
+ $assert_session->pageTextContains('Target page');
+
+ // Clear all caches, then add a translation for the link node.
+ $this->resetAll();
+
+ $this->drupalGet('link-page', $source_url_options);
+ $this->clickLink('Translate');
+ $this->clickLink(t('Add'));
+
+ // Do not change the link field.
+ $edit = [
+ 'title[0][value]' => 'Translated link page',
+ 'path[0][alias]' => '/translated-link-page',
+ ];
+ $this->drupalPostForm(NULL, $edit, 'Save (this translation)');
+
+ $assert_session->pageTextContains('Translated link page');
+
+ // @todo Clicking on the link does not include the language prefix.
+ $this->drupalGet('target-page', $source_url_options);
+ $assert_session->statusCodeEquals(200);
+ $assert_session->pageTextContains('Target page');
+ }
+
+ /**
+ * Data provider for testFromUri().
+ */
+ public function providerLanguage() {
+ return [
+ ['en'],
+ ['fr'],
+ ];
+ }
+
+}