When copy paste title, the page will be broken

[lininu]

As the example, when I paste the title multiple times, the tab is broken and I can't do anything.

[gohabereg]

Hi @lininu
Thanks for report!

Reminder for us: the issue is related to isEmpty method. Tree walker goes to infinite loop.

[neSpecc]

The bug is fixed, but the issue itself requires some more investigation and should not be closed yet.

[cuongdevjs]

any way to fix this?