[Bug Report] when click the element of the last level twice, **@active-item-change** event doesn't work #12072
Description
Element UI version
2.4.4
OS/Browsers version
Chrome 67.0
Vue version
2.5.17-beta.0
Reproduction Link
https://jsfiddle.net/priestlau/vefkuso3/3/
Steps to reproduce
when click the element of the last level twice, @active-item-change event doesn't work
What is Expected?
the argument (val) of @active-item-change event function will be updated
What is actually happening?
when click the element of the last level twice, @active-item-change event doesn't work
click once
click twice
