Steps to reproduce:
Observed behaviour: ve.ce.ContentBranchNode#onTeardown throws an exception because this.root is null.
Expected behaviour: The unbulleting works without an exception.
The TreeModifier change would naturally be the prime suspect, and indeed the broken behaviour was introduced by 37d1512a74bd51038fd837656beb065aa0564d7e .
Should we be reverting TreeModifier again before release then? @Deskana @Jdforrester-WMF
We probably need to. It seems unlikely we can diagnose and fix the issue before then.
Change 377510 had a related patch set uploaded (by Divec; owner: Divec):
[VisualEditor/VisualEditor@master] ve.ce.BranchNode#splice: disconnect nodes fully
It looks like we were leaving zombie connections to nodes long ago torn down, which then reacted badly to TreeModifier causing methods to be called on their non-existent root.
Change 377510 merged by jenkins-bot:
[VisualEditor/VisualEditor@master] ve.ce.BranchNode#splice: disconnect nodes fully
Change 377524 had a related patch set uploaded (by Jforrester; owner: Jforrester):
[mediawiki/extensions/VisualEditor@master] Update VE core submodule to master (dafc7bbe5)
Change 377524 merged by jenkins-bot:
[mediawiki/extensions/VisualEditor@master] Update VE core submodule to master (dafc7bbe5)