Fix QPpdPrintDevice::isDefault

How to test:
 * Have two printers
 * Use lpoptions -d to set the default printer to be one and then the
other
 * Use lpstat -d to check setting the default printer worked
 * Use this simple test program and check the resulting values make
sense
    qDebug() << "DefaultPrinter" << QPrinterInfo::defaultPrinter().printerName();
    const QList<QPrinterInfo> list = QPrinterInfo::availablePrinters();
    for(const QPrinterInfo &pi : list) {
        qDebug() << pi.printerName() << pi.isDefault();
    }

Fixes: QTBUG-70317
Change-Id: I535d11451c568630a374f5c37d8cac32cbb6d3ab
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@qt.io>

1 files changed, 2 insertions, 0 deletions

diff --git a/src/plugins/printsupport/cups/qcupsprintersupport_p.h b/src/plugins/printsupport/cups/qcupsprintersupport_p.h
index 42de28aec0..c2b4895c7f 100644
--- a/src/plugins/printsupport/cups/qcupsprintersupport_p.h
+++ b/src/plugins/printsupport/cups/qcupsprintersupport_p.h
@@ -71,6 +71,8 @@ public:
     QStringList availablePrintDeviceIds() const override;
     QString defaultPrintDeviceId() const override;
 
+    static QString staticDefaultPrintDeviceId();
+
 private:
     QString cupsOption(int i, const QString &key) const;
 };