FlatPage model field url is not unique
|Reported by:||Owned by:||nobody|
|Has patch:||no||Needs documentation:||no|
|Needs tests:||no||Patch needs improvement:||no|
You can create several pages with the same URL, which makes the middleware barf.
I'm not submitting a patch, but I'd imagine it to be as easy as adding an index on (url, site_id).