Thank you for the answer.
The code was created by me and is not in any online repository to see. But I can explain what it does:
- edit_form_after_title hook – I output UL list of tabbed interface here and open the first tab content DIV
- edit_form_after_editor hook – I close the first tab content DIV and output the other content DIVs
The first content DIV is always a visual editor. But as you can see, when I open the DIV in one hook and closing it in another one, this was working fine in WP3.5 as no wrapper was added to those hooks. Once there is a wrapper, it obviously messes up the HTML and the opening of first tab content DIV will never close, while the closing DIV has no opening counterpart. This is causing issues obviously. I would much appreciate if the wrapper in those hooks introduced in WP3.6 was somehow made optional if you are using your own, specially styled wrappers.
I understand, this is something “special” to WordPress, but I find this more screen space efficient than using classical meta boxes for additional page/post options.
(The link to the screenshot above should be still available, please let me know if it’s not.)