#52 It throws an exception to update TreeViewAdv while NodeComboBox is showing a ComboBox.

[YourGod]

How to reproduce:
Set a timer to update the TreeViewAdv in a few seconds.
Click a NodeComboBox column to make the ComboBox drop down.

Cause:
When updating, TreeViewAdv calls HideEditor(), which calls CurrentEditorOwner.EndEdit().
CurrentEditorOwner.EndEdit() calls TreeViewAdv.HideEditor(bool).
TreeViewAdv.HideEditor(bool) sets CurrentEditor.Parent = null.
This causes the NodeComboBox.EditorDropDownClosed().
That makes EditableControl.EndEdit() called again.
That then makes TreeViewAdv.HideEditor(bool) called again.
That makes CurrentEditor = null.
Now it comes back to the next line of CurrentEditor.Parent = null, which is Damn, CurrentEditor.Dispose()
Damn! CurrentEditor is null.

[YourGod]

A quick fix I came up with is to remove the event handler from the ComboBox.
In NodeComboBox.cs,

    protected override void DisposeEditor(Control editor)
    {
        if(editor is ComboBox)
        {
            (editor as ComboBox).DropDownClosed -= EditorDropDownClosed;
        }
    }