When should the permissions check be done?

Hi all,

As implementations of the notifications spec have landed in WebKit and
elsewhere, I wanted to clarify when exactly the permissions check should be
done.

My reading of the specification (
http://www.w3.org/TR/notifications/#showing-a-notification) is that the
permissions check should always (and only) be done when invoking show(). I
think that WebKit may instead do a permissions check in the constructor,
which I suspect is incorrect and may lead to some browser compatibility
issues. Additionally, since the application can call show() at an
arbitrarily later time from invoking the constructor, only checking
permissions in the constructor is incorrect since the user may have changed
his permissions between the constructor and the call to show().

Am I correct in my reading of the specification, and do we perhaps want to
change the spec to do a permission check in both the constructor *and*
show()?

-atw