[Lazarus] VirtualTreeView: Expand/Collapse without OnNodeClick

[Jürgen Hestermann]

I already spend quite a lot of time to find a way around
a certain behaviour in VirtualTreeView (5.5.3-R1) but
with no luck:

When I click on a plus/minus button left of a node in
the tree to collapse/expand all sub-nodes then always
the event OnNodeClick is called too.

It seems to be impossible to start an action by clicking
on a node while still allowing to collapse/expand sub-nodes
as a stand-alone function.
It's annoying to have the event fired when I only want
to expand/collapse nodes.

Is this (again) a bug in VTV or is there a way to
avoid this behaviour?