Linguist segfault in bringToFront

Linguist segfault when the user clicks on a text to be translated and the text is a QListWidget item or a QTreeWidget column defined in a ui file (I only tried with these two).

Commit d56636976643498b9fa688eb9b3029ed9669a8a2 introduced bringToFront to show the widget containing the text to translate but the target.target.object can't be casted to a QWidget.

Here is the backtrace:

0 QObject::isWidgetType qobject.h 137 0x464e1c
1 qobject_cast<QWidget *> qwidget.h 737 0x465050
2 bringToFront formpreviewview.cpp 400 0x4637c5
3 highlightTarget formpreviewview.cpp 416 0x4638a4
4 highlightTargets formpreviewview.cpp 466 0x4639d9
5 FormPreviewView::setSourceContext formpreviewview.cpp 546 0x464454
6 MainWindow::updateSourceView mainwindow.cpp 1995 0x477016
7 MainWindow::selectedMessageChanged mainwindow.cpp 1505 0x471c25
8 MainWindow::qt_static_metacall moc_mainwindow.cpp 360 0x4b816f
9 QMetaObject::activate qobject.cpp 3730 0x7ffff6af208d
10 QMetaObject::activate qobject.cpp 3595 0x7ffff6af189a
11 QItemSelectionModel::currentRowChanged moc_qitemselectionmodel.cpp 490 0x7ffff6a67edb
12 QItemSelectionModel::setCurrentIndex qitemselectionmodel.cpp 1375 0x7ffff6a6467b
13 QAbstractItemView::mousePressEvent qabstractitemview.cpp 1725 0x7ffff79fb8df
14 QTreeView::mousePressEvent qtreeview.cpp 1907 0x7ffff7a499f9
15 QWidget::event qwidget.cpp 8734 0x7ffff7761f31
16 QFrame::event qframe.cpp 544 0x7ffff789605f
17 QAbstractScrollArea::viewportEvent qabstractscrollarea.cpp 1206 0x7ffff793d2b0
18 QAbstractItemView::viewportEvent qabstractitemview.cpp 1685 0x7ffff79fb500
19 QTreeView::viewportEvent qtreeview.cpp 1309 0x7ffff7a46ad8
... <More>

To reproduce:

• create a ui file with a QListWidget;
• add an item with a text to translate;
• generate the ts file;
• open it in linguist;
• click on the text in the QListWidget.

With the attached files, open ags_fr.ts in linguist and click on the "column" text to be translated.