Can't enter @-sign and other characters accessible by ALT modifier in QWebView on Mac OS X

Given: A QWebView with a form field.

It's impossible to enter a character that's created by using the key in conjunction with ALT. On a German keyboard that would be @ (ALT-L) , § (ALT-3), etc. On a Norwegian apparently alt-2 (key combination for @), as indicated by http://stackoverflow.com/questions/18102557/qtwebkit-cant-use-key/18894485#18894485

I've reproduced the issue by compiling and using qt-everywhere-enterprise-src-5.1.1/qtwebkit-examples/examples/webkitwidgets/browser to check that's not our code or usage that's at fault.

See the attached screencast.