workaround for a QGridLayoutEngine bug added

src/layouts/QskStackBox.cpp

@@ -107,6 +107,24 @@ void QskStackBox::layoutItemRemoved( QskLayoutItem*, int index )
         m_data->currentIndex--;
         // currentIndexChanged ???
     }
+
+    auto& engine = this->engine();
+    if ( engine.itemCount() > 0 && engine.itemAt( 0, 0 ) == nullptr )
+    {
+        /*
+            Using QGridLayoutEngine for a stack layout is actually
+            not a good ideas. Until we have a new implementation,
+            we need to work around situations, where the layout does
+            not work properly with having several items in the 
+            same cell. 
+            In this particular situation we need to fix, that we lost
+            the item from engine.q_grid[0].
+            Calling transpose has this side effect.
+            
+         */
+        engine.transpose();
+        engine.transpose(); // reverting the call before
+    }
 }
 
 void QskStackBox::setCurrentIndex( int index )