[Interest] Question about setting QLocale

[Murphy, Sean]

Thanks for the quick reply, Thiago
 
> That's a bug. And there's another bug in your reading/writing of the string, but
> that's besides the point.

Can you go into more details about this? I'd prefer to have no bugs! ;)
 
> QString QDateTime::toString(const QString& format) const {
>     return QLocale::system().toString(*this, format); }
> 
> It should have been QLocale::c(). It's been like the above since 5.2.0 and no one
> noticed. That is, btw, your workaround: use
> 
>   QLocale::c().toString(ample.sampleTime(), "ddd MM/dd/yyyy HH:mm:ss.zzz")

Is that really a bug in Qt though? I'd think as a developer/user in a non-English speaking country that if I were to write out a date object using either the "ddd" or "dddd" options, that I would expect those to show up in my native language. I just wrote a quick little test app, using German instead of Chinese, since I can't read Chinese at all:
main.cpp:
    QApplication a(argc, argv);
    QLocale::setDefault(QLocale(QLocale::German, QLocale::Germany));
    MainWindow w;
    w.show();
    return a.exec();
mainwindow.cpp
    MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
    {
        ui->setupUi(this);
        connect(ui->dateTimeEdit, SIGNAL(dateTimeChanged(QDateTime)),
            SLOT(slotUpdateText()));
        slotUpdateText();
    }

    MainWindow::~MainWindow()
    {
        delete ui;
    }

    void MainWindow::slotUpdateText()
    {
        QDateTime dt = ui->dateTimeEdit->dateTime();
        ui->plainTextEdit->clear();
        QString textString;
        QLocale german(QLocale::German, QLocale::Germany);
        QLocale defaultLocale;
        textString += QString("DateTime: ") + dt.toString("dddd MM/dd/yyyy HH:mm:ss.zzz") + QString("\n");
        textString += QString("Default: ") + defaultLocale.toString(dt, "dddd MM/dd/yyyy HH:mm:ss.zzz") + QString("\n");
        textString += QString("C: ") + QLocale::c().toString(dt, "dddd MM/dd/yyyy HH:mm:ss.zzz") + QString("\n");
        textString += QString("German: ") + german.toString(dt, "dddd MM/dd/yyyy HH:mm:ss.zzz") + QString("\n");
        ui->plainTextEdit->setPlainText(textString);
    }

This produces:
    DateTime: Saturday 01/01/2000 00:00:00.000
    Default: Samstag 01/01/2000 00:00:00.000
    C: Saturday 01/01/2000 00:00:00.000
    German: Samstag 01/01/2000 00:00:00.000

So I'd think your proposal to change QDateTime::toString() to use QLocale::c() would be the wrong behavior. If I'm in Germany, I'd expect to see Samstag, not Saturday. Or am I making some other mistake in my test application (or misunderstanding what QLocale::c() actually does)? I'm assuming that the line: 
  QLocale::setDefault(QLocale(QLocale::German, QLocale::Germany));
Fakes out the rest of the Qt classes to think I'm in Germany, although that first line I print out, where I use QDateTime::toString() and I'm getting it in English kind of says otherwise.
 
> Please file the issue too. I'm not sure we'll be able to change the behaviour
> during 5.x, but we should be able to in 6.0.

Waiting to make sure I understand you correctly!
Sean
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