I've been struggling to set the encoding to UTF-8 for my text/event-stream content. I would like to change the encoding so that clients (e.g. the browser) knows how to interpret umlaut characters correctly (e.g. ä, ü, ö). I posted this problem on Stack Overflow (see Reference URL), where a more detailed description can be found. Thank you.
This should now be fixed, as far as the Content-Type header and text rendered to the response are concerned. Separately I've created #21082 which should not impact this ticket, given the Jackson encoder uses UTF-8 by default, but is closely related nevertheless.