Looks like a browser bug to me. I can't reproduce this using any other browser (checked Firefox, Opera 12, IE 11). The element clearly has 'white-space: nowrap' set and thus shouldn't ever wrap. Funnily, removing it fixes the issue in Chrome (but potentially breaks other browsers).
I can now reprodue this in Chrome on another computer on https://sv.wikipedia.org/wiki/Klas_B%C3%B6%C3%B6k
Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.94 Safari/537.36
Screen Resolution: 1366 px x 768 px Browser Window: 1349 px x 653 px