For qdebug operator<< of pointer types, always check for nullptr

Also, use a consistent syntax for when the pointer is null.

Fixes: QTBUG-135856
Change-Id: I2f5c80a5650b1be6cc0d70cde7cd1e1c1990df9a
Reviewed-by: Christian Ehrlicher <ch.ehrlicher@gmx.de>

src/gui/accessible/qaccessible.cpp

@@ -1972,10 +1972,9 @@ const char *qAccessibleEventString(QAccessible::Event event)
 Q_GUI_EXPORT QDebug operator<<(QDebug d, const QAccessibleInterface *iface)
 {
     QDebugStateSaver saver(d);
-    if (!iface) {
+    if (!iface)
-        d << "QAccessibleInterface(null)";
+        return d << "QAccessibleInterface(0x0)";
-        return d;
+
-    }
     d.nospace();
     d << "QAccessibleInterface(" << Qt::hex << (const void *) iface << Qt::dec;
     if (iface->isValid()) {

src/gui/image/qiconloader.cpp

@@ -441,8 +441,8 @@ QStringList QIconTheme::parents() const
 QDebug operator<<(QDebug debug, const std::unique_ptr<QIconLoaderEngineEntry> &entry)
 {
     QDebugStateSaver saver(debug);
-    debug.noquote() << entry->filename;
+    if (entry) return debug.noquote() << entry->filename;
-    return debug;
+    return debug << "QIconLoaderEngineEntry(0x0)";
 }
 
 QThemeIconInfo QIconLoader::findIconHelper(const QString &themeName,

src/gui/kernel/qevent.cpp

@@ -4055,10 +4055,9 @@ static void formatTabletEvent(QDebug d, const QTabletEvent *e)
 
 QDebug operator<<(QDebug dbg, const QEventPoint *tp)
 {
-    if (!tp) {
+    if (!tp)
-        dbg << "QEventPoint(0x0)";
+        return dbg << "QEventPoint(0x0)";
-        return dbg;
+
-    }
     return operator<<(dbg, *tp);
 }
 
@@ -4098,10 +4097,9 @@ QDebug operator<<(QDebug dbg, const QEvent *e)
 {
     QDebugStateSaver saver(dbg);
     dbg.nospace();
-    if (!e) {
+    if (!e)
-        dbg << "QEvent(this = 0x0)";
+        return dbg << "QEvent(0x0)";
-        return dbg;
+
-    }
     // More useful event output could be added here
     const QEvent::Type type = e->type();
     bool isMouse = false;

src/gui/kernel/qinputdevice.cpp

@@ -377,10 +377,8 @@ QDebug operator<<(QDebug debug, const QInputDevice *device)
     debug.noquote();
 
     debug << "QInputDevice(";
-    if (!device) {
+    if (!device)
-        debug << "0)";
+        return debug << "0x0)";
-        return debug;
-    }
 
     const QInputDevicePrivate *d = QInputDevicePrivate::get(device);
 

src/gui/kernel/qopenglcontext.cpp

@@ -1310,7 +1310,7 @@ QDebug operator<<(QDebug debug, const QOpenGLContext *ctx)
             debug << ", invalid";
         }
     } else {
-        debug << '0';
+        debug << "0x0";
     }
     debug << ')';
     return debug;
@@ -1324,7 +1324,7 @@ QDebug operator<<(QDebug debug, const QOpenGLContextGroup *cg)
     if (cg)
         debug << cg->shares();
     else
-        debug << '0';
+        debug << "0x0";
     debug << ')';
     return debug;
 }

src/gui/kernel/qpointingdevice.cpp

@@ -726,7 +726,7 @@ QDebug operator<<(QDebug debug, const QPointingDevice *device)
         if (device->uniqueId().isValid())
             debug << " uniqueId=" << Qt::hex << device->uniqueId().numericId() << Qt::dec;
     } else {
-        debug << '0';
+        debug << "0x0";
     }
     debug << ')';
     return debug;

src/opengl/qopengltexture.cpp

@@ -4835,7 +4835,7 @@ QDebug operator<<(QDebug debug, const QOpenGLTexture *t)
             << ", features=" << d->features << ", minificationFilter=" << d->minFilter
             << ", magnificationFilter=" << d->magFilter << ", wrapMode=" << d->wrapModes[0];
     } else {
-        debug << '0';
+        debug << "0x0";
     }
     debug << ')';
     return debug;

src/plugins/platforms/windows/qwindowsclipboard.cpp

@@ -57,7 +57,7 @@ static QDebug operator<<(QDebug d, const QMimeData *mimeData)
         if (mimeData->hasUrls())
              d << ", urls=" << mimeData->urls();
     } else {
-        d << '0';
+        d << "0x0";
     }
     d << ')';
     return d;

src/plugins/platforms/windows/qwindowsmenu.cpp

@@ -876,7 +876,7 @@ QDebug operator<<(QDebug d, const QPlatformMenuItem *i)
     if (i)
         static_cast<const QWindowsMenuItem *>(i)->formatDebug(d);
     else
-        d << '0';
+        d << "0x0";
     d << ')';
     return d;
 }
@@ -915,7 +915,7 @@ QDebug operator<<(QDebug d, const QPlatformMenu *m)
         static_cast<const QWindowsMenu *>(m)->formatDebug(d);
         d << ')';
     } else {
-        d << "QPlatformMenu(0)";
+        d << "QPlatformMenu(0x0)";
     }
     return d;
 }
@@ -929,7 +929,7 @@ QDebug operator<<(QDebug d, const QPlatformMenuBar *mb)
     if (mb)
         static_cast<const QWindowsMenuBar *>(mb)->formatDebug(d);
     else
-        d << '0';
+        d << "0x0";
     d << ')';
     return d;
 }

src/plugins/platforms/windows/qwindowsmimeregistry.cpp

@@ -326,7 +326,7 @@ QDebug operator<<(QDebug d, IDataObject *dataObj)
             }
         }
     } else {
-        d << '0';
+        d << "0x0";
     }
     d << ')';
     return d;

src/plugins/platforms/windows/qwindowssystemtrayicon.cpp

@@ -464,7 +464,7 @@ QDebug operator<<(QDebug d, const QWindowsSystemTrayIcon *t)
     if (t)
         t->formatDebug(d);
     else
-        d << '0';
+        d << "0x0";
     d << ')';
     return d;
 }

src/widgets/graphicsview/qgraphicsitem.cpp

@@ -11161,10 +11161,8 @@ QDebug operator<<(QDebug debug, const QGraphicsItem *item)
     QDebugStateSaver saver(debug);
     debug.nospace();
 
-    if (!item) {
+    if (!item)
-        debug << "QGraphicsItem(0)";
+        return debug << "QGraphicsItem(0x0)";
-        return debug;
-    }
 
     if (const QGraphicsObject *o = item->toGraphicsObject())
         debug << o->metaObject()->className();
@@ -11179,7 +11177,7 @@ QDebug operator<<(QDebug debug, const QGraphicsItem *item)
                 debug << ", name=" << w->objectName();
             debug << ')';
         } else {
-            debug << "QWidget(0)";
+            debug << "QWidget(0x0)";
         }
     }
     formatGraphicsItemHelper(debug, item);
@@ -11192,10 +11190,8 @@ QDebug operator<<(QDebug debug, const QGraphicsObject *item)
     QDebugStateSaver saver(debug);
     debug.nospace();
 
-    if (!item) {
+    if (!item)
-        debug << "QGraphicsObject(0)";
+        return debug << "QGraphicsObject(0x0)";
-        return debug;
-    }
 
     debug << item->metaObject()->className() << '(' << static_cast<const void *>(item);
     if (!item->objectName().isEmpty())

src/widgets/graphicsview/qgraphicssceneevent.cpp

@@ -1797,10 +1797,8 @@ QDebug operator<<(QDebug debug, const QGraphicsSceneEvent *event)
 {
     QDebugStateSaver saver(debug);
     debug.nospace();
-    if (!event) {
+    if (!event)
-        debug << "QGraphicsSceneEvent(0)";
+        return debug << "QGraphicsSceneEvent(0x0)";
-        return debug;
-    }
 
     const QEvent::Type type = event->type();
     switch (type) {

src/widgets/kernel/qgesture.cpp

@@ -1080,6 +1080,10 @@ Q_WIDGETS_EXPORT QDebug operator<<(QDebug d, const QGesture *gesture)
 {
     QDebugStateSaver saver(d);
     d.nospace();
+
+    if (!gesture)
+        return d << "QGesture(0x0)";
+
     switch (gesture->gestureType()) {
     case Qt::TapGesture:
         formatGestureHeader(d, "QTapGesture", gesture);
@@ -1148,8 +1152,12 @@ Q_WIDGETS_EXPORT QDebug operator<<(QDebug d, const QGestureEvent *gestureEvent)
 {
     QDebugStateSaver saver(d);
     d.nospace();
-    d << "QGestureEvent(" << gestureEvent->gestures() << ')';
+    d << "QGestureEvent(";
-    return d;
+    if (gestureEvent)
+        d << gestureEvent->gestures();
+    else
+        d << "0x0";
+    return d << ')';
 }
 
 #endif // !QT_NO_DEBUG_STREAM

src/widgets/widgets/qmainwindowlayout.cpp

@@ -146,8 +146,9 @@ QDebug operator<<(QDebug debug, const QDockAreaLayout &layout)
 
 QDebug operator<<(QDebug debug, const QMainWindowLayout *layout)
 {
-    debug << layout->layoutState.dockAreaLayout;
+    if (layout)
-    return debug;
+        return debug << layout->layoutState.dockAreaLayout;
+    return debug << "QMainWindowLayout(0x0)";
 }
 
 // Use this to dump item lists of all populated main window docks.

tests/auto/other/macnativeevents/qnativeevents.cpp

@@ -180,13 +180,13 @@ QString QNativeModifierEvent::toString() const
 
 QDebug operator<<(QDebug d, QNativeEvent *e)
 {
-    Q_UNUSED(e);
+    if (e)
-    return d << e->toString();
+        return d << e->toString();
+    return d << "QNativeEvent(0x0)";
 }
 
 QDebug operator<<(QDebug d, const QNativeEvent &e)
 {
-    Q_UNUSED(e);
     return d << e.toString();
 }
 

tests/manual/diaglib/debugproxystyle.cpp

@@ -14,10 +14,9 @@ QDebug operator<<(QDebug debug, const QStyleOption *option)
     QDebugStateSaver saver(debug);
     debug.noquote();
     debug.nospace();
-    if (!option) {
+    if (!option)
-        debug << "QStyleOption(0)";
+        return debug << "QStyleOption(0x0)";
-        return debug;
+
-    }
     if (const QStyleOptionViewItem *ivo = qstyleoption_cast<const QStyleOptionViewItem *>(option)) {
         debug << "QStyleOptionViewItem(";
         debug << ivo->index;