Route.php urlencodes params once but decodes twice, causing params like xx%2Fyy to fail. #15269

This is a (multiple allowed):

• bug

• enhancement

• feature-discussion (RFC)

• CakePHP Version: 4.2.1

What you did

Obviously this is not exactly what I am trying to do, but this is the simplest way I can show what is happening.

// ProductsController.php
public function index(): ?Response
{
    $url = Router::url(['action' => 'test', 'xx/yy']); //products/test/xx%2Fyy
    return $this->redirect($url);
}

public function test()
{
    var_dump(func_get_args());
    exit;
}

What happened

1. I get redirected to http://localhost:8080/products/test/xx%2Fyy
2. The var dump shows:

/var/www/src/Controller/ProductsController.php:54:
array (size=2)
  0 => string 'xx' (length=2)
  1 => string 'yy' (length=2)

What you expected to happen

1. To get redirected to http://localhost:8080/products/test/xx%2Fyy
2. The var dump to show:

/var/www/src/Controller/ProductsController.php:54:
array (size=1)
  0 => string 'xx/yy' (length=5)

What is causing this

In d5283af urldecode got added. Which is still present in 4.2.1.

if (!preg_match($compiledRoute, urldecode($url), $route)) {
    return null;
}

This line of code decodes the entire URL before routing the request. Causing this bug. Changing it to if(!preg_match($compiledRoute, $url, $route)) fixed the problem.

Please be aware that all the params are indvidually encoded on Route.php#L794 and decoded on Route.php#L575

So we are now encoding once, and decoding twice, which doesn't make any sense to me.

Disclaimer

I fully understand why this is happening, because of international URI (IRI) which might contain characters like آموزش and I respect that. But I think we should think of another solution, because very basic functionality and expected behavior is now broken.