[Gmsh] Bug in test_move_point_parametric_triangle

[Peter Wainwright]

Amazingly, I have discovered a potentially serious bug in the routines
which perform edge collapse in the BDS_Mesh.

Owing to this, it is possible for a point to collapse onto a linear
boundary creating slivers (triangles with collinear points).

The problem is that the sides of the triangle, a and b, are not
recalculated after the point is moved.  Thus, area_final and area_init
are always equal!  So the test for slivers is defeated.

I attach a simple patch to fix this.

That aside, gmsh works great for me. Many thanks for this program!

Peter Wainwright


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