#10988 Fix QItemSelectionModel warning when exiting application

The tree view in PdmUiTreeSelectionEditor is deleted using deleteLater(),
while the models are children of the editor and are deleted immediately.
Detach the view from the models in the destructor, otherwise pending events
in the view may operate on a selection model whose model has been destroyed.

Fwk/AppFwk/cafUserInterface/cafPdmUiTreeSelectionEditor.cpp

@@ -157,6 +157,12 @@ PdmUiTreeSelectionEditor::PdmUiTreeSelectionEditor()
 //--------------------------------------------------------------------------------------------------
 PdmUiTreeSelectionEditor::~PdmUiTreeSelectionEditor()
 {
+    // The tree view is deleted using deleteLater() in ~PdmUiFieldEditorHandle, while m_model and m_proxyModel are
+    // children of this editor and are deleted immediately. Detach the view from the models, otherwise pending events
+    // in the view (e.g. deferred QHeaderView::reset) may operate on a selection model whose model has been destroyed,
+    // causing "QItemSelectionModel: Selecting when no model has been set will result in a no-op."
+    // https://github.com/OPM/ResInsight/issues/10988
+    if ( m_treeView ) m_treeView->setModel( nullptr );
 }
 
 //--------------------------------------------------------------------------------------------------