French keyboard's dot key (numeric keypad) does not work as input

I'm working on a French Windows 7 computer.

When I try to type a decimal number in a QDoubleSpinBox control or a QLineEdit validated by a QDoubleValidator, pressing the dot numeric keypad button does nothing....I would expect it to insert a decimal separator!

Like Microsoft Excel does: if I press "1" "." and "2" from the numeric keypad, is writes "1,2" in the selected cell (because "," is the decimal separator on my machine).

I attached a main.cpp as an example.

 
#include <QApplication>
#include <QVBoxLayout>
#include <QLabel>
#include <QSpinBox>
#include <QDialog>
#include <QDoubleValidator>
#include <QLineEdit>

class Dialog : public QDialog
{
public:
    Dialog()
    {
        QVBoxLayout* layout = new QVBoxLayout( this );

        layout->addWidget( new QLabel( QLocale().toString( 3.14 ), this ) );
        layout->addWidget( new QDoubleSpinBox( this ) );

        QLineEdit* edit = new QLineEdit( this );
        edit->setValidator( new QDoubleValidator() );
        layout->addWidget( edit );
    }
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    Dialog w;
    w.show();

    return a.exec();
}

When compiled and executed, here's what I see:

• The QLabel displays "3,14" which means french QLocale is correctly used (else, it would display 3.14, english default stype). OK
• The QDoubleSpinBox diplays "0,00". OK
• I can type a decimal value in the spinbox using the ',' standard keyboard key. OK
• I cannot type a decimal value in the spinbox using the '.' standard keyboard key. OK
• But when I press the dot key from my numerical French keypad, nothing happens! This is supposed to enter a decimal separator, whatever locale setting is being used!

Note: Qt 4.7 used to work fine displaying and using "." as a separator, Qt 5.2 appears to be smart enough to automatically change "." to "," on my PC, but not smart enough to make the keypad "." key work