I am using the default CDT mesh refiner. I sometimes hit an assertion when refining.

I am running tip of tree CGAL as of Feb 12 - SHA c624d3d

terminate called after throwing an instance of 'CGAL::Assertion_exception'
what(): CGAL ERROR: assertion violation!
Expr: n == zone.fh
File: /usr/local/include/CGAL/Mesh_2/Refine_edges.h
Line: 434
Aborted (core dumped)

I've created a gist (https://gist.github.com/petersadro/55470eccde4ce8df3684) with the backtrace, example code, and data to reproduce the issue.

Sorry for the large amount of data. I actually pared down the free points to the minimum to still reproduce the problem. Removing the constraints is problematic.

Thanks,
Pete