9 files changed, 24 insertions, 8 deletions
diff --git a/src/plugins/platforms/xcb/gl_integrations/qxcbglintegrationplugin.h b/src/plugins/platforms/xcb/gl_integrations/qxcbglintegrationplugin.h
index d5a0af97b0..b18248570f 100644
--- a/src/plugins/platforms/xcb/gl_integrations/qxcbglintegrationplugin.h
+++ b/src/plugins/platforms/xcb/gl_integrations/qxcbglintegrationplugin.h
@@ -54,7 +54,7 @@ class Q_XCB_EXPORT QXcbGlIntegrationPlugin : public QObject
 {
     Q_OBJECT
 public:
-        explicit QXcbGlIntegrationPlugin(QObject *parent = 0)
+        explicit QXcbGlIntegrationPlugin(QObject *parent = nullptr)
             : QObject(parent)
         { }
 
diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp
index b751aaf8a3..34895caaa2 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qxcbglxintegration.cpp
@@ -164,7 +164,11 @@ bool QXcbGlxIntegration::handleXcbEvent(xcb_generic_event_t *event, uint respons
                 XUnlockDisplay(xdisplay);
                 locked = false;
                 auto eventType = m_connection->nativeInterface()->nativeEventType();
+#  if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+                qintptr result = 0;
+#  else
                 long result = 0;
+#  endif
                 handled = dispatcher->filterNativeEvent(eventType, &ev, &result);
             }
 #endif
diff --git a/src/plugins/platforms/xcb/qxcbconnection.cpp b/src/plugins/platforms/xcb/qxcbconnection.cpp
index 06d1000993..d27a288feb 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection.cpp
@@ -438,7 +438,11 @@ const char *xcb_protocol_request_codes[] =
 
 void QXcbConnection::handleXcbError(xcb_generic_error_t *error)
 {
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    qintptr result = 0;
+#else
     long result = 0;
+#endif
     QAbstractEventDispatcher* dispatcher = QAbstractEventDispatcher::instance();
     if (dispatcher && dispatcher->filterNativeEvent(m_nativeInterface->nativeEventType(), error, &result))
         return;
@@ -535,7 +539,11 @@ void QXcbConnection::handleXcbEvent(xcb_generic_event_t *event)
     if (Q_UNLIKELY(lcQpaEvents().isDebugEnabled()))
         printXcbEvent(lcQpaEvents(), "Event", event);
 
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    qintptr result = 0; // Used only by MS Windows
+#else
     long result = 0; // Used only by MS Windows
+#endif
     if (QAbstractEventDispatcher *dispatcher = QAbstractEventDispatcher::instance()) {
         if (dispatcher->filterNativeEvent(m_nativeInterface->nativeEventType(), event, &result))
             return;
diff --git a/src/plugins/platforms/xcb/qxcbconnection.h b/src/plugins/platforms/xcb/qxcbconnection.h
index bbfa252881..7cf25d41a6 100644
--- a/src/plugins/platforms/xcb/qxcbconnection.h
+++ b/src/plugins/platforms/xcb/qxcbconnection.h
@@ -108,7 +108,7 @@ public:
     virtual void handleXIMouseEvent(xcb_ge_event_t *, Qt::MouseEventSource = Qt::MouseEventNotSynthesized) {}
     virtual void handleXIEnterLeave(xcb_ge_event_t *) {}
 #endif
-    virtual QXcbWindow *toWindow() { return 0; }
+    virtual QXcbWindow *toWindow() { return nullptr; }
 };
 
 typedef QHash<xcb_window_t, QXcbWindowEventListener *> WindowMapper;
@@ -366,7 +366,7 @@ private:
 
     WindowMapper m_mapper;
 
-    Qt::MouseButtons m_buttonState = 0;
+    Qt::MouseButtons m_buttonState = nullptr;
     Qt::MouseButton m_button = Qt::NoButton;
 
     QXcbWindow *m_focusWindow = nullptr;
diff --git a/src/plugins/platforms/xcb/qxcbcursor.h b/src/plugins/platforms/xcb/qxcbcursor.h
index 5bc806381c..488988cbe9 100644
--- a/src/plugins/platforms/xcb/qxcbcursor.h
+++ b/src/plugins/platforms/xcb/qxcbcursor.h
@@ -83,7 +83,7 @@ public:
     QPoint pos() const override;
     void setPos(const QPoint &pos) override;
 
-    static void queryPointer(QXcbConnection *c, QXcbVirtualDesktop **virtualDesktop, QPoint *pos, int *keybMask = 0);
+    static void queryPointer(QXcbConnection *c, QXcbVirtualDesktop **virtualDesktop, QPoint *pos, int *keybMask = nullptr);
 
 #ifndef QT_NO_CURSOR
     xcb_cursor_t xcbCursor(const QCursor &c) const
diff --git a/src/plugins/platforms/xcb/qxcbdrag.h b/src/plugins/platforms/xcb/qxcbdrag.h
index c19008c04b..1388e68acc 100644
--- a/src/plugins/platforms/xcb/qxcbdrag.h
+++ b/src/plugins/platforms/xcb/qxcbdrag.h
@@ -86,7 +86,7 @@ public:
     void handlePosition(QPlatformWindow *w, const xcb_client_message_event_t *event);
     void handleLeave(QPlatformWindow *w, const xcb_client_message_event_t *event);
     void handleDrop(QPlatformWindow *, const xcb_client_message_event_t *event,
-                    Qt::MouseButtons b = 0, Qt::KeyboardModifiers mods = 0);
+                    Qt::MouseButtons b = nullptr, Qt::KeyboardModifiers mods = nullptr);
 
     void handleStatus(const xcb_client_message_event_t *event);
     void handleSelectionRequest(const xcb_selection_request_event_t *event);
@@ -109,7 +109,7 @@ private:
     void init();
 
     void handle_xdnd_position(QPlatformWindow *w, const xcb_client_message_event_t *event,
-                              Qt::MouseButtons b = 0, Qt::KeyboardModifiers mods = 0);
+                              Qt::MouseButtons b = nullptr, Qt::KeyboardModifiers mods = nullptr);
     void handle_xdnd_status(const xcb_client_message_event_t *event);
     void send_leave();
 
diff --git a/src/plugins/platforms/xcb/qxcbobject.h b/src/plugins/platforms/xcb/qxcbobject.h
index 1b98d9346b..931bed9ec1 100644
--- a/src/plugins/platforms/xcb/qxcbobject.h
+++ b/src/plugins/platforms/xcb/qxcbobject.h
@@ -47,7 +47,7 @@ QT_BEGIN_NAMESPACE
 class QXcbObject
 {
 public:
-    QXcbObject(QXcbConnection *connection = 0) : m_connection(connection) {}
+    QXcbObject(QXcbConnection *connection = nullptr) : m_connection(connection) {}
 
     void setConnection(QXcbConnection *connection) { m_connection = connection; }
     QXcbConnection *connection() const { return m_connection; }
diff --git a/src/plugins/platforms/xcb/qxcbwindow.cpp b/src/plugins/platforms/xcb/qxcbwindow.cpp
index 9382488b74..396b47001d 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.cpp
+++ b/src/plugins/platforms/xcb/qxcbwindow.cpp
@@ -1657,7 +1657,11 @@ bool QXcbWindow::requestSystemTrayWindowDock()
 bool QXcbWindow::handleNativeEvent(xcb_generic_event_t *event)
 {
     auto eventType = connection()->nativeInterface()->nativeEventType();
+#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
+    qintptr result = 0; // Used only by MS Windows
+#else
     long result = 0; // Used only by MS Windows
+#endif
     return QWindowSystemInterface::handleNativeEvent(window(), eventType, event, &result);
 }
 
diff --git a/src/plugins/platforms/xcb/qxcbwindow.h b/src/plugins/platforms/xcb/qxcbwindow.h
index f98cd8a74d..e4a04f5308 100644
--- a/src/plugins/platforms/xcb/qxcbwindow.h
+++ b/src/plugins/platforms/xcb/qxcbwindow.h
@@ -166,7 +166,7 @@ public:
     bool needsSync() const;
 
     void postSyncWindowRequest();
-    void clearSyncWindowRequest() { m_pendingSyncRequest = 0; }
+    void clearSyncWindowRequest() { m_pendingSyncRequest = nullptr; }
 
     QXcbScreen *xcbScreen() const;