admin-ajax does notices

[hakre]

Minor Problem. Attached patch just shows where.

[nacin]

Lower down in the file when we check for $_POST, we surround a switch with an isset.

Here when we check for $_GET (with the patch), if not set it would allow an "wp_ajax_" action to execute.

Also, when we check for $_REQUEST['action'] for nopriv, we check if it is empty.

We should probably standardize all of them to prevent an empty action from triggering a hook.

[nacin]

Was handled elsewhere in 3.0.