Relative stream possible issue with pointers

[weierophinney]

I was looking through stream implementation. Relative stream and the stream it wraps are sharing same pointer, right?
So if we rewind wrapped stream, read on relative will return data before offset position.
Also tell() will give negative position, which is out of bounds error.

This shared pointer in streams looks extremely bug prone to me.

May be on seekable streams we should store pointer locally, set it before performing operation and record new position after doing it?

As simplified example:

public function read()
{
    $this->seek($this->position, SEEK_SET);
    $result = fread($resource, $length);
    $this->position = $this->tell();
    return $result;
}

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Originally posted by @Xerkus at zendframework/zend-diactoros#147