steps to reproduce

1. load the attached zul
2. hover to the <div> with "disabled button tooltip" and trigger the tooltip popup with a disabled button to shows up
3. hover to the disabled button

current result

the open popup closes itself immediately

expected result

the popup keeps open

debug info

• if you open the tooltip of another <div> with "normal tooltip" and hover on an enabled button. The popup keeps open and doesn't close itself.
• this issue only happens since 7.0.0. 6.x doesn't happen.
• the disabled button doesn't fire onMouseOver event, but the button still fires the event under 6.x.
• firefox still fires onmouseover event on a disabled element

workaround

• use pointer-events:none
  <popup id="ppd2" style="padding:20px">
  <button disabled="true" style="pointer-events:none">disabled</button>
  </popup>