Lazy adapter can cause infinite recursion

[linaori]

I made a mistake in my configuration which lead me to infinite recursion (segfaulting). Turns out I had the name of the lazy storage in my environment variable, trying to infinitely create itself through LazyFactory::create()

parameters:
    env(RECURSION_SOURCE): recursion

flysystem:
    storages:
        recursion:
            adapter: 'lazy'
            options:
                source: '%env(RECURSION_SOURCE)%' #also breaks if I just fill in "recursion" here

Due to the nature of being a runtime calculation on which storage to use, I think the factory should probably validate that it's not trying to initialize the lazy adapter as the lazy adapter. If multiple levels of factories should be support (lazy -> lazy -> real) my suggestion won't solve it, but this would be a fix for my scenario:

class LazyFactory
{
    private $storages;

    public function __construct(ContainerInterface $storages)
    {
        $this->storages = $storages;
    }

    public function createStorage(string $source, string $storageName)
    {
        if ($source === $storageName) {
            throw new \InvalidArgumentException('... some message saying you try to initialize the lazy adapter');
        }

        if (!$this->storages->has($source)) {
            throw new \InvalidArgumentException('You have requested a non-existent source storage "'.$source.'" in lazy storage "'.$storageName.'".');
        }

        return $this->storages->get($source);
    }
}

[tgalopin]

This is a good idea indeed, if you're open to create PR I'd gladly merge it, otherwise I'll have a look :)