QDataStream will read a QFile opened with mode "Text". What would have been nice is if the QDataStream had checked the the QIODevice was in Text mode and warned me. For instance triggered an assert like:

Q_ASSERT_X(dataStream.device()->isTextModeEnabled() == false, "Danger", "The device is a text device");

Update: We never insert asserts (forcing the application to crash) because of this, but we can insert a qWarning.