StreamWrapper::stream_stat() should not always return an array

[chapa]

PHP version: >= 8.1

Description

StreamWrapper::stream_stat() is returning an array no matter what, this can cause problems when the inner stream has a size of null, because it's then transformed to 0. The information "I don't know the size of this stream" is transformed to "this stream is empty".

Also, I'm wondering, why url_stat() (implemented in #156) does return a mode and a size of 0 unconditionally.

How to reproduce

$r = fopen('https://google.com', 'r');
assert(fstat($r) === false);

$stream = Utils::streamFor($r);
assert($stream->getSize() === null);

$r2 = StreamWrapper::getResource($stream);
assert(fstat($r2) === false); // This fails

$stream2 = Utils::streamFor($r2);
assert($stream2->getSize() === null); // This fails too (0 is returned)

Possible Solution

#594

Additional context

I'm trying to send a request with Guzzle, that request has a null-sized stream body wrapped in StreamWrapper as explained above (for some reasons that I cannot bypass), and Guzzle itself seems to rely on the fact that a 0-sized body should not be sent in a request : https://github.com/guzzle/guzzle/blob/2779e868a00289e1b1fd854af030c43a06f4bcb4/src/Handler/CurlFactory.php#L251.

As a result, the request is sent without it's body.