Issue #3490639 by dcam, seanb: Checking for duplicate emails in...

Issue #3490639 by dcam, seanb: Checking for duplicate emails in user_requirements() does not take langcode into account

core/modules/user/src/Hook/UserRequirements.php

@@ -49,6 +49,7 @@ public function runtime(): array {
     $query->addExpression('LOWER(mail)', 'lower_mail');
     $query->isNotNull('mail');
     $query->groupBy('lower_mail');
+    $query->groupBy('langcode');
     $query->having('COUNT(uid) > :matches', [':matches' => 1]);
     $conflicts = $query->countQuery()->execute()->fetchField();
 

core/modules/user/tests/src/Kernel/UserRequirementsTest.php

@@ -5,6 +5,7 @@
 namespace Drupal\Tests\user\Kernel;
 
 use Drupal\KernelTests\KernelTestBase;
+use Drupal\language\Entity\ConfigurableLanguage;
 use Drupal\Tests\user\Traits\UserCreationTrait;
 
 /**
@@ -70,4 +71,21 @@ public function testBlankUserEmails(): void {
     $this->assertArrayNotHasKey('conflicting emails', $output);
   }
 
+  /**
+   * Tests that the requirements check does not flag user translations.
+   */
+  public function testTranslatedUserEmail(): void {
+    \Drupal::service('module_installer')->install(['language']);
+    ConfigurableLanguage::createFromLangcode('is')->save();
+
+    $output = $this->moduleHandler->invoke('user', 'runtime_requirements');
+    $this->assertArrayNotHasKey('conflicting emails', $output);
+
+    $user = $this->createUser([], 'User A', FALSE, ['mail' => 'unique@example.com']);
+    $user->addTranslation('is')->save();
+
+    $output = $this->moduleHandler->invoke('user', 'runtime_requirements');
+    $this->assertArrayNotHasKey('conflicting emails', $output);
+  }
+
 }