title: QTableWidget Drag Item not Removing when Dropping on Invalid area
body: <p>Pretty much as the tittle says, when i drag an item from QTableWidget it adds a child to ui->table->children, and then it launches ChildAdded event to my eventFilter, the problem is that if i drop the dragged item into an area that doesn't accept dropping that child won't be removed from ui->table->children whereas releasing the dragged item within an area that has dropping enabled it will, and also launches ChildRemoved event.</p>
  
  <p>Here is my init code:</p>
  
  <pre><code>MainWindow::MainWindow(QWidget *parent) :
      QMainWindow(parent),
      m_ui(new Ui::MainWindow)
  {
      m_ui-&gt;setupUi(this);
  
      m_ui-&gt;left_table-&gt;installEventFilter(this);
      m_ui-&gt;right_table-&gt;installEventFilter(this);
  
      m_ui-&gt;left_table-&gt;setColumnCount(1);
      m_ui-&gt;left_table-&gt;setRowCount(25);
      m_ui-&gt;left_table-&gt;setHorizontalHeaderLabels({"Source"});
      m_ui-&gt;left_table-&gt;horizontalHeader()-&gt;setStretchLastSection(true);
      m_ui-&gt;left_table-&gt;setAcceptDrops(false);
      m_ui-&gt;left_table-&gt;setDragEnabled(true);
  
      m_ui-&gt;right_table-&gt;setColumnCount(1);
      m_ui-&gt;right_table-&gt;setHorizontalHeaderLabels({"Receiver"});
      m_ui-&gt;right_table-&gt;horizontalHeader()-&gt;setStretchLastSection(true);
      m_ui-&gt;right_table-&gt;setAcceptDrops(true);
  
      for (int i = 0; i &lt; 25; ++i) {
          m_ui-&gt;left_table-&gt;setItem(i, 0, new QTableWidgetItem(QString::number(i)));
      }
  
      qDebug() &lt;&lt; "Left childs: " &lt;&lt; m_ui-&gt;left_table-&gt;children().size();
  }
  </code></pre>
  
  <p>and the event filter:</p>
  
  <pre><code>bool MainWindow::eventFilter(QObject *watched, QEvent *event)
  {
      if (event-&gt;type() == QEvent::ChildAdded || event-&gt;type() == QEvent::ChildRemoved) {
          qDebug() &lt;&lt; "Object: " &lt;&lt; watched-&gt;objectName()
                   &lt;&lt; " Event: " &lt;&lt; event-&gt;type()
                   &lt;&lt; "Childs: " &lt;&lt; m_ui-&gt;left_table-&gt;children().size();
      }
      return false;
  }
  </code></pre>
  
  <p>Example of dropping on invalid area, this wont remove the child added before: </p>
  
  <p><a href="https://i.stack.imgur.com/awV7W.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/awV7W.png" alt="enter image description here"></a></p>
  
  <p>Example of dropping on valid area, this will remove the child and call the ChildRemoved event:</p>
  
  <p><a href="https://i.stack.imgur.com/Nsv8S.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Nsv8S.png" alt="enter image description here"></a></p>