[FrameworkBundle] Check for class existence before is_subclass_of

Author: chalasr

DependencyInjection/Compiler/AddConsoleCommandPass.php

@@ -38,6 +38,10 @@ public function process(ContainerBuilder $container)
 
             $class = $container->getParameterBag()->resolveValue($definition->getClass());
             if (!is_subclass_of($class, 'Symfony\\Component\\Console\\Command\\Command')) {
+                if (!class_exists($class, false)) {
+                    throw new \InvalidArgumentException(sprintf('Class "%s" used for service "%s" cannot be found.', $class, $id));
+                }
+
                 throw new \InvalidArgumentException(sprintf('The service "%s" tagged "console.command" must be a subclass of "Symfony\\Component\\Console\\Command\\Command".', $id));
             }
             $container->setAlias('console.command.'.strtolower(str_replace('\\', '_', $class)), $id);