I have an issue with the use of window.opener.
Whenever I use window.open("url"), the opened window will reference window.opener fine, but when I use GM_openInTab that claims to be equivalent (and I use it for the cross browser compatibility because opening in tabs is essential) it's window.opener value for the child window is null.
How come GM_openInTab's opened window window.opener is null? How can I get around this?