fix #41, a crash when a dock was removed

--removing connections on xwindowinterface destructor
--removing connections on dockview destructor
--remove xwindowinterface that was created from
visibilitymanager in its destructor

app/dockview.cpp

@@ -98,12 +98,20 @@ DockView::DockView(Plasma::Corona *corona, QScreen *targetScreen)
     DockCorona *dcorona = qobject_cast<DockCorona *>(this->corona());
 
     if (dcorona) {
-        connect(dcorona, &DockCorona::containmentsNoChanged, this, &DockView::updateDocksCount);
+        connections << connect(dcorona, &DockCorona::containmentsNoChanged, this, &DockView::updateDocksCount);
     }
 }
 
 DockView::~DockView()
 {
+    qDebug() << "dock view deleting...";
+
+    foreach (auto var, connections) {
+        QObject::disconnect(var);
+    }
+
+    qDebug() << "dock view connections deleted...";
+
     if (m_visibility) {
         m_visibility->deleteLater();
     }
@@ -125,7 +133,7 @@ void DockView::init()
         m_timerGeometry.start();
     });
     
-    connect(&WindowSystem::self(), &WindowSystem::compositingChanged
+    connections << connect(&WindowSystem::self(), &WindowSystem::compositingChanged
     , this, [&]() {
         emit compositingChanged();
     } , Qt::QueuedConnection);

app/dockview.h

@@ -96,6 +96,7 @@ public:
     bool tasksPresent() const;
     
     void adaptToScreen(QScreen *screen);
+    void unload();
     
     QQmlListProperty<QScreen> screens();
     static int countScreens(QQmlListProperty<QScreen> *property);
@@ -175,6 +176,8 @@ private:
     
     QPointer<VisibilityManager> m_visibility;
 
+    QList<QMetaObject::Connection> connections;
+    
     void initWindow();
 
     void addAppletActions(QMenu *desktopMenu, Plasma::Applet *applet, QEvent *event);

app/visibilitymanager.cpp

@@ -64,6 +64,7 @@ VisibilityManagerPrivate::VisibilityManagerPrivate(PlasmaQuick::ContainmentView
 VisibilityManagerPrivate::~VisibilityManagerPrivate()
 {
     wm->removeDockStruts();
+    wm->deleteLater();
 }
 
 inline void VisibilityManagerPrivate::setMode(Dock::Visibility mode)
@@ -386,6 +387,7 @@ bool VisibilityManagerPrivate::event(QEvent *ev)
                 raiseDock(true);
 
             break;
+
         case QEvent::Leave:
             if (!containsMouse)
                 break;
@@ -395,17 +397,20 @@ bool VisibilityManagerPrivate::event(QEvent *ev)
             updateHiddenState();
 
             break;
+
         case QEvent::DragEnter:
             dragEnter = true;
             emit q->mustBeShown();
 
             break;
+
         case QEvent::DragLeave:
         case QEvent::Drop:
             dragEnter = false;
             updateHiddenState();
 
             break;
+
         case QEvent::Show:
             wm->setDockDefaultFlags();
             restoreConfig();
@@ -490,4 +495,3 @@ void VisibilityManager::updateDockGeometry(const QRect &geometry)
 }
 //! END: VisibilityManager implementation
 }
-

app/xwindowinterface.cpp

@@ -35,10 +35,10 @@ XWindowInterface::XWindowInterface(QQuickWindow *const view, QObject *parent)
 {
     Q_ASSERT(view != nullptr);
     
-    connect(KWindowSystem::self(), &KWindowSystem::activeWindowChanged
+    connections << connect(KWindowSystem::self(), &KWindowSystem::activeWindowChanged
                            , this, &AbstractWindowInterface::activeWindowChanged);
 
-    connect(KWindowSystem::self()
+    connections << connect(KWindowSystem::self()
                            , static_cast<void (KWindowSystem::*)(WId, NET::Properties, NET::Properties2)>
                            (&KWindowSystem::windowChanged)
                            , this, &XWindowInterface::windowChangedProxy);
@@ -52,16 +52,16 @@ XWindowInterface::XWindowInterface(QQuickWindow *const view, QObject *parent)
         }
     };
     
-    connect(KWindowSystem::self(), &KWindowSystem::windowAdded, this, addWindow);
+    connections << connect(KWindowSystem::self(), &KWindowSystem::windowAdded, this, addWindow);
     
-    connect(KWindowSystem::self(), &KWindowSystem::windowRemoved, [this](WId wid) {
+    connections << connect(KWindowSystem::self(), &KWindowSystem::windowRemoved, [this](WId wid) {
         if (std::find(m_windows.cbegin(), m_windows.cend(), wid) != m_windows.end()) {
             m_windows.remove(wid);
             emit windowRemoved(wid);
         }
     });
     
-    connect(KWindowSystem::self(), &KWindowSystem::currentDesktopChanged
+    connections << connect(KWindowSystem::self(), &KWindowSystem::currentDesktopChanged
                            , this, &AbstractWindowInterface::currentDesktopChanged);
 
     // fill windows list
@@ -72,7 +72,13 @@ XWindowInterface::XWindowInterface(QQuickWindow *const view, QObject *parent)
 
 XWindowInterface::~XWindowInterface()
 {
+    qDebug() << "x window interface deleting...";
 
+    foreach (auto var, connections) {
+        QObject::disconnect(var);
+    }
+
+    qDebug() << "x window interface connections removed...";
 }
 
 void XWindowInterface::setDockDefaultFlags()

app/xwindowinterface.h

@@ -54,6 +54,8 @@ private:
     void windowChangedProxy(WId wid, NET::Properties prop1, NET::Properties2 prop2);
     
     WId m_desktopId;
+
+    QList<QMetaObject::Connection> connections;
 };
 
 }
@@ -62,4 +64,3 @@ private:
 
 
 
-