Background

Duplicates in confancestors appear if collaborative editing is enabled, and dark feature editor.ajax.save.disable is enabled as well.

How to reproduce

1. Enable collaborative editing
2. Enable editor.ajax.save.disable dark-feature
3. Create a new page and save it
4. Check that duplicates appeared in confancestor table

 Technical details

When editor.ajax.save.disable is enabled and user saves a page, docreatepage.action is called. Method AbstractCreatePageAction.doAdd calls assignParentPage(draft, getParentPage()) method which adds a child, and adds ancestors to the child.

But the child already had ancestors before, so assignParentPage adds duplicates.

The method "assignParentPage" is not called if collaborative editing is disabled.

To check if the dark-feature is enabled, go to <CONFLUENCE_URL>/admin/darkfeatures.action