Resolves: tdf#108705 remove grabs on widget before destroying it

Change-Id: If02a0b4340788db638c74b98e855258145643452
Reviewed-on: https://gerrit.libreoffice.org/39165Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

vcl/unx/gtk3/gtk3gtkframe.cxx

@@ -836,6 +836,11 @@ GtkSalFrame::~GtkSalFrame()
 
     delete m_pIMHandler;
 
+    //tdf#108705 remove grabs on event widget before
+    //destroying event widget
+    while (m_nGrabLevel)
+        removeGrabLevel();
+
     GtkWidget *pEventWidget = getMouseEventWidget();
     for (auto handler_id : m_aMouseSignalIds)
         g_signal_handler_disconnect(G_OBJECT(pEventWidget), handler_id);