Yes I agree with you, after the 'choose polyline' prompt the polyline should highlight showing the nodes.

I personally think this may be a bug here!

@Andrew - is this a bug?

@Clive: It's a consistency thing that might not be obvious but probably makes sense after having a closer look:

Tools should never change the current selection unless:
- they are selection tools
or
- they are modification tools which delete entities or create new entities.

The tool to delete nodes of a polyline does not require a selection prior to using the tool. It has no connection at all to selected entities and should ignore the selection and leave it unchanged. Other tools in this category are: trim, round, etc. The user might use such tools while a selection exists. It is not desirable that this existing selection is changed by a tool that does not operate on a selection at all.

Polyline nodes (like any other reference points) are highlighted only when the polyline entity is selected. Choosing an entity for one single operation (delete nodes, trim, round, etc) is not the same as selecting an entity for a future operation.

@caigner

Would be nice if you could make the nodes of the selected polyline visible.

Note that the polyline it not necessarily selected - it is only chosen for one single operation.

Or don’t ask again for selecting a polyline if it was already selected before the tool was chosen

There might be several entities selected when this tool it used. This selection must remain unchanged.

Currently the workaround is to first select the polyline (which shows the nodes), then choose the tool, then AGAIN select the polyline and then start clicking on the nodes.

Correct terminology would be:

"First select the polyline (which shows the nodes), then choose the tool, then choose the polyline to work on and then start clicking on the nodes."
This is indeed the way to go if your polyline nodes are not obviously visible (i.e. sharp corners).

Thanks for the explanation Andrew.