Issue #1942682 by zaporylie, deadbeef, jhedstrom, dawehner: Blank detail view...

Issue #1942682 by zaporylie, deadbeef, jhedstrom, dawehner: Blank detail view in dblog for deleted users

core/modules/dblog/src/Controller/DbLogController.php

@@ -242,12 +242,12 @@ public function overview() {
    */
   public function eventDetails($event_id) {
     $build = array();
-    if ($dblog = $this->database->query('SELECT w.*, u.name, u.uid FROM {watchdog} w INNER JOIN {users_field_data} u ON w.uid = u.uid WHERE w.wid = :id AND u.default_langcode = 1', array(':id' => $event_id))->fetchObject()) {
+    if ($dblog = $this->database->query('SELECT w.*, u.uid FROM {watchdog} w LEFT JOIN {users} u ON u.uid = w.uid WHERE w.wid = :id', array(':id' => $event_id))->fetchObject()) {
       $severity = RfcLogLevel::getLevels();
       $message = $this->formatMessage($dblog);
       $username = array(
         '#theme' => 'username',
-        '#account' => $this->userStorage->load($dblog->uid),
+        '#account' => $this->userStorage->load($dblog->uid ? $dblog->uid : 0),
       );
       $rows = array(
         array(

core/modules/dblog/src/Tests/DbLogTest.php

@@ -698,4 +698,33 @@ protected function assertLogMessage($log_message, $message) {
     // string in xpath() to query the Document Object Model (DOM).
     $this->assertLink(html_entity_decode($message_text), 0, $message);
   }
+
+  /**
+   * Tests that the details page displays correctly for a temporary user.
+   */
+  public function testTemporaryUser() {
+    // Create a temporary user.
+    $tempuser = $this->drupalCreateUser();
+    $tempuser_uid = $tempuser->id();
+
+    // Log in as the admin user.
+    $this->drupalLogin($this->adminUser);
+
+    // Generate a single watchdog entry.
+    $this->generateLogEntries(1, array('user' => $tempuser, 'uid' => $tempuser_uid));
+    $wid = db_query('SELECT MAX(wid) FROM {watchdog}')->fetchField();
+
+    // Check if the full message displays on the details page.
+    $this->drupalGet('admin/reports/dblog/event/' . $wid);
+    $this->assertText('Dblog test log message');
+
+    // Delete the user.
+    user_delete($tempuser->id());
+    $this->drupalGet('user/' . $tempuser_uid);
+    $this->assertResponse(404);
+
+    // Check if the full message displays on the details page.
+    $this->drupalGet('admin/reports/dblog/event/' . $wid);
+    $this->assertText('Dblog test log message');
+  }
 }