tiles: Evacuate windows in CustomTile::remove()

src/tiles/customtile.cpp

@@ -10,6 +10,7 @@
 #include "customtile.h"
 #include "core/output.h"
 #include "tilemanager.h"
+#include "window.h"
 
 namespace KWin
 {
@@ -273,6 +274,7 @@ void CustomTile::remove()
 
     manager()->model()->beginRemoveTile(this);
     parentT->removeChild(this);
+    m_parentTile = nullptr;
     manager()->model()->endRemoveTile();
     manager()->tileRemoved(this);
 
@@ -320,6 +322,11 @@ void CustomTile::remove()
         }
     }
 
+    const auto windows = std::exchange(m_windows, {});
+    for (Window *window : windows) {
+        window->setTile(m_tiling->bestTileForPosition(window->moveResizeGeometry().center()));
+    }
+
     deleteLater(); // not using "delete this" because QQmlEngine will crash
 }
 

src/tiles/tile.h

@@ -151,7 +151,6 @@ protected:
     void insertChild(int position, Tile *item);
     void removeChild(Tile *child);
 
-private:
     QList<Tile *> m_children;
     QList<Window *> m_windows;
     Tile *m_parentTile;