GridTools::compute_active_cell_halo_layer() not working for PBC

[peterrum]

While having a look at the implementation of GridTools::compute_active_cell_halo_layer(), I have noticed that they cannot work for periodicity, since they do not consider coinciding vertices here:

dealii/source/grid/grid_tools_dof_handlers.cc

Lines 748 to 751 in 0c0c455

	for (const auto &cell : mesh.active_cell_iterators())
	if (predicate(cell)) // True predicate --> Part of subdomain
	for (const auto v : cell->vertex_indices())
	locally_active_vertices_on_subdomain[cell->vertex_index(v)] = true;

They should however, as done here:

dealii/source/grid/tria_description.cc

Lines 455 to 467 in cfebfb5

	for (const auto v : cell->vertex_indices())
	{
	vertices_owned_by_locally_owned_cells[cell->vertex_index(
	v)] = true;
	const auto coinciding_vertex_group =
	vertex_to_coinciding_vertex_group.find(
	cell->vertex_index(v));
	if (coinciding_vertex_group !=
	vertex_to_coinciding_vertex_group.end())
	for (const auto &co_vertex : coinciding_vertex_groups.at(
	coinciding_vertex_group->second))
	vertices_owned_by_locally_owned_cells[co_vertex] = true;
	}

This also implies that p:s:T with artificial cells does not work either for periodicity.