until now, when the query segment started exactly on a vertex/edge/facet,
the constructor was setting _cur to one cell incident to this vertex/edge/facet,
not necessarily the one that was intersected by the segment query
this commit fixes it by introducing the function
`jump_to_intersecting_cell()`, that changes _cur to point to the right cell
previous commit was dealing with the case where entry is a vertex,
here we deal with all entry types
PLUS fix the edge - facet - vertex degenerate case
when the query segment passes exactly through a vertex, avoid returning more
than one cell containing this vertex
operator++ iterates until it finds a cell which does not contain this vertex
This reverts commit 8b68ab3459.
# Conflicts:
# Triangulation_3/include/CGAL/Triangulation_segment_traverser_3.h
NOTE
in the degenerate case where the query passes exactly through an edge
(i.e. through both of its vertices), it could happen that the iterator
"circulates" around the edge, whithout finding a way to get out of this
infinite loop
randomness is re-introduced to avoid this
to check whether the computed next cell really does intersect the query segment
[source, target]
we do not deal with infinite cell because intersection does not mean much.
Jane Tournois
Laurent Rineau
Andreas Fabri
Thijs van Lankveld