fix two serious crashes from config window

--first is inside the freeEdges function call
on destruction
--the second is also in the app's destruction
because of the call to a destructed containment
through m_containment. This variable was deleted

app/dockconfigview.cpp

@@ -38,7 +38,6 @@ namespace Latte {
 DockConfigView::DockConfigView(Plasma::Containment *containment, DockView *dockView, QWindow *parent)
     : PlasmaQuick::ConfigView(containment, parent),
       m_blockFocusLost(false),
-      m_containment(containment),
       m_dockView(dockView)
 {
     connections << connect(dockView, &QObject::destroyed, this, &QObject::deleteLater);
@@ -78,7 +77,7 @@ void DockConfigView::init()
     rootContext()->setContextProperty(QStringLiteral("dock"), m_dockView);
     rootContext()->setContextProperty(QStringLiteral("dockConfig"), this);
     rootContext()->setContextObject(new KLocalizedContext(this));
-    auto source = QUrl::fromLocalFile(m_containment->corona()->kPackage().filePath("lattedockconfigurationui"));
+    auto source = QUrl::fromLocalFile(m_dockView->containment()->corona()->kPackage().filePath("lattedockconfigurationui"));
     setSource(source);
     syncSlideEffect();
 }
@@ -90,13 +89,13 @@ inline Qt::WindowFlags DockConfigView::wFlags() const
 
 void DockConfigView::syncGeometry()
 {
-    if (!m_containment || !rootObject())
+    if (!m_dockView->containment() || !rootObject())
         return;
 
-    const auto location = m_containment->location();
+    const auto location = m_dockView->containment()->location();
     const auto sGeometry = screen()->geometry();
 
-    switch (m_containment->formFactor()) {
+    switch (m_dockView->containment()->formFactor()) {
         case Plasma::Types::Horizontal: {
             const QSize size(rootObject()->width(), rootObject()->height());
             setMaximumSize(size);
@@ -137,12 +136,12 @@ void DockConfigView::syncGeometry()
 
 void DockConfigView::syncSlideEffect()
 {
-    if (!m_containment)
+    if (!m_dockView->containment())
         return;
 
     KWindowEffects::SlideFromLocation slideLocation{KWindowEffects::NoEdge};
 
-    switch (m_containment->location()) {
+    switch (m_dockView->containment()->location()) {
         case Plasma::Types::TopEdge:
             slideLocation = KWindowEffects::TopEdge;
             break;
@@ -178,8 +177,8 @@ void DockConfigView::showEvent(QShowEvent *ev)
     syncGeometry();
     syncSlideEffect();
 
-    if (m_containment)
+    if (m_dockView && m_dockView->containment())
-        m_containment->setUserConfiguring(true);
+        m_dockView->containment()->setUserConfiguring(true);
 
     m_screenSyncTimer.start();
     QTimer::singleShot(400, this, &DockConfigView::syncGeometry);
@@ -187,9 +186,8 @@ void DockConfigView::showEvent(QShowEvent *ev)
 
 void DockConfigView::hideEvent(QHideEvent *ev)
 {
-    if (m_containment && m_dockView) {
+    if (m_dockView && m_dockView->containment())
-        m_containment->setUserConfiguring(false);
+        m_dockView->containment()->setUserConfiguring(false);
-    }
 
     QQuickWindow::hideEvent(ev);
 }

app/dockconfigview.h

@@ -67,7 +67,6 @@ private slots:
 private:
     bool m_blockFocusLost;
 
-    Plasma::Containment *m_containment{nullptr};
     QPointer<DockView> m_dockView;
     QTimer m_screenSyncTimer;
 

app/dockview.cpp

@@ -95,6 +95,11 @@ DockView::~DockView()
     this->disconnect();
     qDebug() << "dock view connections deleted...";
 
+    if (m_configView) {
+        m_configView->hide();
+        m_configView->deleteLater();
+    }
+
     if (m_visibility) {
         delete m_visibility;
     }
@@ -431,6 +436,11 @@ bool DockView::event(QEvent *e)
 
 QList<int> DockView::freeEdges() const
 {
+    if (!corona() || !containment()) {
+        const QList<int> emptyEdges;
+        return emptyEdges;
+    }
+
     const auto edges = corona()->freeEdges(containment()->screen());
     QList<int> edgesInt;
 
@@ -445,13 +455,8 @@ void DockView::closeApplication()
 {
     DockCorona *dockCorona = qobject_cast<DockCorona *>(this->corona());
 
-    if (dockCorona) {
+    if (dockCorona)
-        //m_configView->hide();
-        if (m_configView)
-            m_configView->deleteLater();
-
         dockCorona->closeApplication();
-    }
 }
 
 QVariantList DockView::containmentActions()