Twenty Fifteen: menu's show page content, screwing up layout

[anonymized_5853594]

When I switched to Twenty Fifteen, my menu got scambled and doesn't list all menu items because of it. It listed a whole lot of the text on the actual page, instead of what I expected the layout of a menu to look like. When this happens, it also doesn't show the secondary menu items.

I remade my normal menu from scratch and with this new version, the menu looked just fine.

The only difference I could see between the two versions is that the original uses title attributes with all menu items and the new version doesn't...

I have replicated the error by adding title attributes to the new version, but I can't seem to reproduce the error consistently.
Even so, the original menu keeps screwing up the layout of the menu and the new one doesn't.

Screenshots:
​http://misc.tieptoep.nl/img/2015_menu_main.png The original menu, with screwed up layout.
​http://misc.tieptoep.nl/img/2015_menu_test.png The copy, which looks fine.

[TomHarrigan]

I don't think this is a bug. Here's what I believe is happening:

With your problematic menu, go to Screen Options, check the "Description" box, as seen in the screenshot below. In your menu items, the large amount of text you're seeing on the front end should be visible in the "Description" box.

So, the extra text is being caused by the contents of the Description area in your original menu, where as the new menu did not have this field filled out.

[anonymized_5853594]

Ah... You're right!
I never saw that, so I never considered looking at it.

I'm sorry for filing it as a bug.
Should I close the ticket? Or better yet, set it as invalid?