--- /dev/null
+<?php
+
+namespace Drupal\path\Plugin\Validation\Constraint;
+
+use Symfony\Component\Validator\Constraint;
+
+/**
+ * Validation constraint for changing path aliases in pending revisions.
+ *
+ * @Constraint(
+ * id = "PathAlias",
+ * label = @Translation("Path alias.", context = "Validation"),
+ * )
+ */
+class PathAliasConstraint extends Constraint {
+
+ public $message = 'You can only change the URL alias for the <em>published</em> version of this content.';
+
+}