It turned out that nv.getDatabaseRequestHandler() returned NULL; using this pointer to call one of DatabaseRequestHandler's methods is of course illegal.
I patched it by adding: if (nv.getDatabaseRequestHandler())"
From Robert Osfield, reordered the addition of the nv.getDatabaseRequestHandler() check to allow the
default traverse() to be called when no database handling is attached to the visitor.
that removeChild(Node*), removeChild(uint) and equivilant Geode methods are
now inline methods, not designed to be overriden, and seperated out the
multiple remove method to be called removeChildren(uint, uint) which is
now the only virtual method. There removeChildren is now the method to
override in subclasses.
This reorganisation requires some call code to be rename removeChild usage
to removeChildren.
