Qt's ICU-based QTextCodec instance handling US-ASCCI is broken (QTBUG-83081) by not reporting when it encounters data it cannot handle. Which screws any conversions done as test, like the use with
QTextCodec::canEncode(...) but also code inspecting directly the success of a tried conversion by checking the
invalidChars number of the passed
QTextCodec::ConverterState instance, like done in
As long as a fix is not in Qt, it would be good to have a work-around at least for the US-ASCCI charset, as might be used in some occasions within PIM code, at least unit tests can be triggering this codec.