3 files changed, 10 insertions, 0 deletions
diff --git a/src/plugins/printsupport/cups/qcupsprintengine.cpp b/src/plugins/printsupport/cups/qcupsprintengine.cpp
index 724ff5b98b..d7cd18f1d1 100644
--- a/src/plugins/printsupport/cups/qcupsprintengine.cpp
+++ b/src/plugins/printsupport/cups/qcupsprintengine.cpp
@@ -85,6 +85,12 @@ void QCupsPrintEngine::setProperty(PrintEnginePropertyKey key, const QVariant &v
         // Get the named page size from the printer if supported
         d->setPageSize(d->m_printDevice.supportedPageSize(value.toString()));
         break;
+    case PPK_Duplex: {
+        QPrint::DuplexMode mode = QPrint::DuplexMode(value.toInt());
+        if (mode != d->duplex && d->m_printDevice.supportedDuplexModes().contains(mode))
+            d->duplex = mode;
+        break;
+    }
     case PPK_PrinterName:
         d->changePrinter(value.toString());
         break;
diff --git a/src/plugins/printsupport/cups/qppdprintdevice.cpp b/src/plugins/printsupport/cups/qppdprintdevice.cpp
index 75e8a8bf26..7a6acf8b78 100644
--- a/src/plugins/printsupport/cups/qppdprintdevice.cpp
+++ b/src/plugins/printsupport/cups/qppdprintdevice.cpp
@@ -387,6 +387,9 @@ void QPpdPrintDevice::loadDuplexModes() const
     // If still no result, or not added in PPD, then add None
     if (m_duplexModes.size() == 0 || !m_duplexModes.contains(QPrint::DuplexNone))
         m_duplexModes.append(QPrint::DuplexNone);
+    // If have both modes, then can support DuplexAuto
+    if (m_duplexModes.contains(QPrint::DuplexLongSide) && m_duplexModes.contains(QPrint::DuplexShortSide))
+        m_duplexModes.append(QPrint::DuplexAuto);
     m_haveDuplexModes = true;
 }
 
diff --git a/src/plugins/printsupport/windows/qwindowsprintdevice.cpp b/src/plugins/printsupport/windows/qwindowsprintdevice.cpp
index 0feea5ea74..a0a549da6f 100644
--- a/src/plugins/printsupport/windows/qwindowsprintdevice.cpp
+++ b/src/plugins/printsupport/windows/qwindowsprintdevice.cpp
@@ -378,6 +378,7 @@ void QWindowsPrintDevice::loadDuplexModes() const
     DWORD duplex = DeviceCapabilities((LPWSTR)m_id.utf16(), NULL, DC_DUPLEX, NULL, NULL);
     if (int(duplex) == 1) {
         // TODO Assume if duplex flag supports both modes
+        m_duplexModes.append(QPrint::DuplexAuto);
         m_duplexModes.append(QPrint::DuplexLongSide);
         m_duplexModes.append(QPrint::DuplexShortSide);
     }