Symfony version(s) affected

7.0

Description

In a Symfony bundle (https://github.com/symfonycorp/connect) we have this:

namespace SymfonyCorp\Connect;

use Symfony\Component\HttpKernel\Bundle\Bundle;

class SymfonyConnectBundle extends Bundle
{
    public function getContainerExtension(): ?ExtensionInterface
    {
        if (null === $this->extension) {
            $this->extension = new SymfonyConnectExtension();
        }

        return $this->extension;
    }

    // ...
}

It works fine in all Symfony versions up to and including 6.4.

But, in 7.0 (beta2) we're seeing this error:

Typed property Symfony\Component\HttpKernel\Bundle\Bundle::$extension
must not be accessed before initialization.

The error happens because this line in 6.4:

Turned into this line in 7.0:

If I make this change in Symfony code, everything works again:

-protected ExtensionInterface|false $extension;
+protected ExtensionInterface|false|null $extension = null;

So, what should we do here? Thanks!

How to reproduce

Use this bundle https://github.com/symfonycorp/connect in a Symfony 7 application.

Possible Solution

No response

Additional Context

No response