Issue #2536052 by znerol, jungle, Rishi Kulshreshtha, smustgrave, alexpott, dawehner, quietone: Remove try...catch from SessionHandler::write

core/lib/Drupal/Core/Session/SessionHandler.php

@@ -5,7 +5,6 @@ namespace Drupal\Core\Session;
 use Drupal\Component\Utility\Crypt;
 use Drupal\Core\Database\Connection;
 use Drupal\Core\DependencyInjection\DependencySerializationTrait;
-use Drupal\Core\Utility\Error;
 use Symfony\Component\HttpFoundation\RequestStack;
 use Symfony\Component\HttpFoundation\Session\Storage\Proxy\AbstractProxy;
 
@@ -71,32 +70,18 @@ class SessionHandler extends AbstractProxy implements \SessionHandlerInterface {
    */
   #[\ReturnTypeWillChange]
   public function write(#[\SensitiveParameter] $sid, $value) {
-    // The exception handler is not active at this point, so we need to do it
-    // manually.
-    try {
-      $request = $this->requestStack->getCurrentRequest();
-      $fields = [
-        'uid' => $request->getSession()->get('uid', 0),
-        'hostname' => $request->getClientIP(),
-        'session' => $value,
-        'timestamp' => REQUEST_TIME,
-      ];
-      $this->connection->merge('sessions')
-        ->keys(['sid' => Crypt::hashBase64($sid)])
-        ->fields($fields)
-        ->execute();
-      return TRUE;
-    }
-    catch (\Exception $exception) {
-      require_once DRUPAL_ROOT . '/core/includes/errors.inc';
-      // If we are displaying errors, then do so with no possibility of a
-      // further uncaught exception being thrown.
-      if (error_displayable()) {
-        print '<h1>Uncaught exception thrown in session handler.</h1>';
-        print '<p>' . Error::renderExceptionSafe($exception) . '</p><hr />';
-      }
-      return FALSE;
-    }
+    $request = $this->requestStack->getCurrentRequest();
+    $fields = [
+      'uid' => $request->getSession()->get('uid', 0),
+      'hostname' => $request->getClientIP(),
+      'session' => $value,
+      'timestamp' => REQUEST_TIME,
+    ];
+    $this->connection->merge('sessions')
+      ->keys(['sid' => Crypt::hashBase64($sid)])
+      ->fields($fields)
+      ->execute();
+    return TRUE;
   }
 
   /**

core/modules/system/tests/modules/session_test/session_test.routing.yml

@@ -161,3 +161,13 @@ session_test.has_bag_flag:
     no_cache: TRUE
   requirements:
     _access: 'TRUE'
+
+session_test.trigger_write_exception:
+  path: '/session-test/trigger-write-exception'
+  defaults:
+    _title: 'Trigger an exception when the session is written'
+    _controller: '\Drupal\session_test\Controller\SessionTestController::triggerWriteException'
+  options:
+    no_cache: TRUE
+  requirements:
+    _access: 'TRUE'

core/modules/system/tests/modules/session_test/src/Controller/SessionTestController.php

@@ -245,4 +245,43 @@ class SessionTestController extends ControllerBase {
     );
   }
 
+  /**
+   * Trigger an exception when the session is written.
+   *
+   * @param \Symfony\Component\HttpFoundation\Request $request
+   *   The request object.
+   */
+  public function triggerWriteException(Request $request) {
+    $session = $request->getSession();
+    $session->set('test_value', 'Ensure session contains some data');
+
+    // Move sessions table out of the way.
+    $schema = \Drupal::database()->schema();
+    $schema->renameTable('sessions', 'sessions_tmp');
+
+    // There needs to be a session table, otherwise
+    // InstallerRedirectTrait::shouldRedirectToInstaller() will instruct the
+    // handleException::handleException to redirect to the installer.
+    $schema->createTable('sessions', [
+      'description' => "Fake sessions table missing some columns.",
+      'fields' => [
+        'sid' => [
+          'description' => "A fake session ID column.",
+          'type' => 'varchar_ascii',
+          'length' => 128,
+          'not null' => TRUE,
+        ],
+      ],
+      'primary key' => ['sid'],
+    ]);
+
+    drupal_register_shutdown_function(function () {
+      $schema = \Drupal::database()->schema();
+      $schema->dropTable('sessions');
+      $schema->renameTable('sessions_tmp', 'sessions');
+    });
+
+    return new Response();
+  }
+
 }

core/modules/system/tests/src/Functional/Session/SessionTest.php

@@ -358,6 +358,20 @@ class SessionTest extends BrowserTestBase {
     $this->assertSession()->statusCodeEquals(200);
   }
 
+  /**
+   * Test exception thrown during session write close.
+   */
+  public function testSessionWriteError() {
+    // Login to ensure a session exists.
+    $user = $this->drupalCreateUser([]);
+    $this->drupalLogin($user);
+
+    // Trigger an exception in SessionHandler::write().
+    $this->expectExceptionMessageMatches("/^Drupal\\\\Core\\\\Database\\\\DatabaseExceptionWrapper:/");
+    $this->drupalGet('/session-test/trigger-write-exception');
+    $this->assertSession()->statusCodeEquals(500);
+  }
+
   /**
    * Reset the cookie file so that it refers to the specified user.
    */