--- /dev/null
+<?php
+
+namespace Drupal\Tests\system\Functional\Update;
+
+use Drupal\FunctionalTests\Update\UpdatePathTestBase;
+
+/**
+ * Tests handling of existing initial keys during updates.
+ *
+ * @see https://www.drupal.org/project/drupal/issues/2925550
+ *
+ * @group Update
+ */
+class EntityUpdateInitialTest extends UpdatePathTestBase {
+
+ /**
+ * {@inheritdoc}
+ */
+ protected function setDatabaseDumpFiles() {
+ $this->databaseDumpFiles = [
+ __DIR__ . '/../../../fixtures/update/drupal-8.0.0-rc1-filled.standard.entity_test_update.php.gz',
+ __DIR__ . '/../../../fixtures/update/drupal-8.entity-test-initial.php',
+ ];
+ }
+
+ /**
+ * Tests that a pre-existing initial key in the field schema is not a change.
+ */
+ public function testInitialIsIgnored() {
+ $this->runUpdates();
+ }
+
+}