I corrected a bug in the tube operator that could cause it to crash if
the data had previously had an operation applied that removed some of the
cells such as the subset operator.  The bug was introduced in Oct 2008,
when it was enhanced to look for loops.  The logic that was added did not
take into account the number of times a node was referenced resulting in
an uninitialized memory reference.  The code now only considers nodes that
are referenced twice.



git-svn-id: http://visit.ilight.com/svn/visit/trunk/src@9300 18c085ea-50e0-402c-830e-de6fd14e8384