`copy_tree` implicitly drops collinear points

[abdelq]

There is implicit point compression on a copy_tree call, which was surprising to see while debugging some 3rd party code that uses KLayout's API. I'd assume it would copy the geometry as is, and I couldn't find any comment or flag in the doc about this.

Here is a link to a small unit test that I used to confirm and reproduce the issue: abdelq@9ce4d1f

[klayoutmatthias]

Thanks for the bug report. That is not intended. I think it can be fixed.

I'd just like to warn about the expectation to preserve collinear points. OASIS for example is more efficient when these points are dropped, so they are not necessarily preserved in all cases.

Matthias