[8.x] Use duplicate instead of createFromBase to clone request when routes are cached

[rodrigopedra]

Closes #42403

When routes are compiled, the CompiledRouteCollection@requestWithoutTrailingSlash method uses the static method Request@createFromBase to clone a Illuminate\Http\Request.

When the request is a JSON request, this call causes the request's JSON payload to be parsed twice:

• first when the request is captured
• and then when CompiledRouteCollection@requestWithoutTrailingSlash is called, which, as noticed on issue [9.x] memory exhausted because JSON payload is unwanted parsed twice by Illuminate\Http\Request::createFromBase #42403 , can cause a noticeable increase on memory usage when processing large JSON payloads.

Actually, issue #42403 describes a memory exhaust scenario with default PHP configuration.

The doc block on CompiledRouteCollection@requestWithoutTrailingSlash states this method Get a cloned instance of the given request without any trailing slash on the URI, so as the original $request is already a Illuminate\Http\Request, e.g. it is already bootstrapped, we can safely change this call to use the Request@duplicate method, which internally actually clones the request object, avoiding the double json_encode parsing.

This PR:

• Changes the method CompiledRouteCollection@requestWithoutTrailingSlash to call Request@duplicate instead of Request@captureFromBase, to clone the current request.

Notes:

This behavior only happens when routes are cached.

I didn't add any tests, as I would need to mock the Illuminate\Http\Request and assert its static method createFromBase was not called twice.

I don't know how to properly mock static methods. If someone can guide me on how to do it, I will appreciate.

[driesvints]

Thanks @rodrigopedra