Wrong charset when adding new categories containing unicode characters

[hovenko]

When adding categories in administration that contains unicode characters such as the norwegian characters "æøå" they get displayed as a non-printable character (displaying a question mark).

Nyf�dte

I'm not sure what charset is used for these characters. Changing the browser to display as ISO-8859-1 or (-15) also displays it wrong.

Nyfï¿œdte

The category was added from the categories page, "wp-admin/categories.php". This page uses an Ajax call to add a new category. I guess this is where it goes wrong.

This is when using Konqueror on Linux. Firefox gets it right.

[janbrasna]

Make sure it's not related to one of the following Konqueror bugs:

• ​http://bugs.kde.org/show_bug.cgi?id=110768
• ​http://bugs.kde.org/show_bug.cgi?id=130234
• ​http://bugs.kde.org/show_bug.cgi?id=140005

However, it's related to #8572 anyways. More info there. (As such, I'm closing this as a dupe, trying to consolidate all the bugs into one meta-ticket. Feel free to reopen if the future fix of said bug doesn't help.)