Dialog: multiple modal dialog zindex conflicts

[L_K_W]

Look at the following code in the ui.dialog file:

$(document).bind($.ui.dialog.overlay.events, function(event) {
// stop events if the z-index of the target is < the z-index of the overlay
    return ($(event.target).zIndex() >= $.ui.dialog.overlay.maxZ);
});

The value of '$.ui.dialog.overlay.maxZ' will be changed if a second modal dialog opend and this will cause the events handler return false. For example, if you click a radio on the first dialog to open a new second dialog, this raido will never be checked.

I think we should use a tmp var saved before the bind operation.

[Scott González]

Duplicate of #8172.
Closing as duplicate of the newer ticket because the description in the newer ticket is much better and it contains a test case.