ServerRequest::fromGlobals() should use new static()

[bkdotcom]

Currently:

class MyExtendedRequest extends \GuzzleHttp\Psr7\ServerRequest
{
}

// This creates a ServerRequest object, not a MyExtendedRequest object :(
$request = MyExtendedRequest::fromGlobals(); 

fromGlobals calls new ServerRequest(...). it should call new static(...)
Workaround is for extended class to extend (recreate) the fromGlobals method (but with static)

[sagikazarmark]

This has been rejected once. Please see #158 and #159 for explanations.

[bkdotcom]

Oops... my quick search for existing issues came up empty...

To Quote @kael-shipman comment on #158

The second thing I did was try to instantiate my new subclass using the fromGlobals method, which, by all counts, should have worked as expected. To my surprise, it didn't, and I had to debug it, eventually discovering what I thought was a bug and reporting it. This wasted my time and yours, and obvious @ilyar's, too, when he found it and reported it, and will probably waste other people's time as more people run into this and try to report it (and yours along with it as you close the repeat bug reports and point people to this discussion).

I'm just wanting a few Slim-like methods, isXhr(), getCookieParam(), getQueryParam, etc

The arguments against LSB (PSR7 doesn't define constructor / ServerRequest is a value object) frankly don't make sense to me. But I respect your judgement.

Suggestion: add a // this is not a bug comment to the code

[sagikazarmark]

@bkdotcom What about plain old functions?

function isXhr(ServerRequestInterface $request)
{
    return true;
}

IMO that fits better your use case since it would work with any implementation and you don't have to check or make sure that the request is always your request type.