Unset Window::tile() when the window is closed

If a window is closed, its geometry should not change. The window has to
leave its assigned tile so it's not possibly moved or resized.

src/internalwindow.cpp

@@ -335,6 +335,7 @@ void InternalWindow::destroyWindow()
 
     Q_EMIT closed();
 
+    setTile(nullptr);
     workspace()->removeInternalWindow(this);
     m_handle = nullptr;
 

src/window.cpp

@@ -101,9 +101,7 @@ Window::Window()
 
 Window::~Window()
 {
-    if (m_tile) {
-        m_tile->removeWindow(this);
-    }
+    Q_ASSERT(!m_tile);
     Q_ASSERT(m_blockGeometryUpdates == 0);
 }
 
@@ -3611,6 +3609,7 @@ void Window::setTile(Tile *tile)
     m_tile = tile;
 
     if (m_tile) {
+        Q_ASSERT(!isDeleted());
         m_tile->addWindow(this);
     }
 

src/x11window.cpp

@@ -407,6 +407,7 @@ void X11Window::releaseWindow(bool on_shutdown)
         if (isInteractiveMoveResize()) {
             Q_EMIT interactiveMoveResizeFinished();
         }
+        setTile(nullptr);
         workspace()->rulebook()->discardUsed(this, true); // Remove ForceTemporarily rules
         StackingUpdatesBlocker blocker(workspace());
         stopDelayedInteractiveMoveResize();
@@ -485,6 +486,7 @@ void X11Window::destroyWindow()
         if (isInteractiveMoveResize()) {
             Q_EMIT interactiveMoveResizeFinished();
         }
+        setTile(nullptr);
         workspace()->rulebook()->discardUsed(this, true); // Remove ForceTemporarily rules
         StackingUpdatesBlocker blocker(workspace());
         stopDelayedInteractiveMoveResize();

src/xdgshellwindow.cpp

@@ -300,6 +300,7 @@ void XdgSurfaceWindow::destroyWindow()
         leaveInteractiveMoveResize();
         Q_EMIT interactiveMoveResizeFinished();
     }
+    setTile(nullptr);
     m_configureTimer->stop();
     qDeleteAll(m_configureEvents);
     m_configureEvents.clear();