Fixed an issue that does not work with symfony 3.4

[chihiro-adachi]

When running the test with symfony 3.4RC1, the following error occurred.

2) Tests\Provider\ConsoleServiceProviderTest::testLintTwigCommand
Symfony\Component\Console\Exception\LogicException: The command defined in "Knp\Command\Twig\DebugCommand" cannot have an empty name.

PHP Fatal error:  Uncaught Symfony\Component\Console\Exception\LogicException: The command defined in "Knp\Command\Twig\LintCommand" cannot have an empty name. in /Users/chihiro_adachi/repos/ConsoleServiceProvider/vendor/symfony/console/Application.php:432
Stack trace:
#0 /Users/chihiro_adachi/repos/ConsoleServiceProvider/Knp/Provider/ConsoleServiceProvider.php(49): Symfony\Component\Console\Application->add(Object(Knp\Command\Twig\LintCommand))
#1 /Users/chihiro_adachi/repos/ConsoleServiceProvider/vendor/pimple/pimple/src/Pimple/Container.php(118): Knp\Provider\ConsoleServiceProvider->Knp\Provider\{closure}(Object(Silex\Application))
#2 /Users/chihiro_adachi/repos/ConsoleServiceProvider/bin/console(28): Pimple\Container->offsetGet('console')
#3 {main}
  thrown in /Users/chihiro_adachi/repos/ConsoleServiceProvider/vendor/symfony/console/Application.php on line 432

It seems that the constructor of Symfony/Console/ Command has been changed, and the command name can not be acquired. I confirmed that it works by defining $defaultName.

[GregOriol]

The checks on Symfony's Command seem indeed much more restrictive now: the static defaultName must be defined on the called class, can't be on one of its parents as it was here. This PR should be accepted if Symfony's implementation is not going to change.

[SinSquare]

👍

[GregOriol]

Hey, it has been almost a month now and this issue is causing big problems with the latest symfony versions, maybe it's time to merge this request?

[skalpa]

Thank you @chihiro-adachi

[GregOriol]

@skalpa Could you release this version so we can get it as stable when using symfony 3.4?