I

src/Driver/Database/mysqli/Connection.php

@@ -220,11 +220,4 @@ protected function driverTransactionManager(): TransactionManagerInterface {
     return new TransactionManager($this);
   }
 
-  /**
-   * {@inheritdoc}
-   */
-  public function startTransaction($name = '') {
-    return $this->transactionManager()->push($name);
-  }
-
 }

src/Driver/Database/mysqli/TransactionManager.php

@@ -54,7 +54,9 @@ protected function rollbackClientTransaction(): bool {
    * {@inheritdoc}
    */
   protected function commitClientTransaction(): bool {
-    return $this->connection->getClientConnection()->commit();
+    $success = $this->connection->getClientConnection()->commit();
+dump([__METHOD__, $success]);
+    return $success;
   }
 
 }

tests/src/Kernel/mysqli/TransactionTest.php

@@ -113,4 +113,15 @@ public function testConnectionDeprecations(): void {
     $this->markTestSkipped('Skipping this for mysqli');
   }
 
+
+  /**
+   * A post-transaction callback for testing purposes.
+   */
+  public function rootTransactionCallback(bool $success): void {
+dump([__METHOD__, $success]);
+    $this->postTransactionCallbackAction = $success ? 'rtcCommit' : 'rtcRollback';
+    $this->insertRow($this->postTransactionCallbackAction);
+  }
+
+
 }