Unicode 6 changed the bidi-mirroring properties of some characters (see http://unicode.org/versions/corrigendum6.html). Of these characters, the characters 2019,201A (single quotes), 201D and 201E (double quotes) are used in Hebrew (and are to be included in a soon-to-be-released new Hebrew Keyboard Layout standard).

Qt still uses the old definitions. The result is a regression-by-default: If I wrote this comment in an RTL language (like Hebrew), using the proper Hebrew quotes (open with U201E and close with U201D), it would be presented incorrectly in any Qt-based browser.