fix tags not being copied

panda/src/pgraph/pandaNode.I

@@ -144,6 +144,10 @@ CData(const PandaNode::CData &copy) :
   _fixed_internal_bound(copy._fixed_internal_bound)
 {
   _net_collide_mask = CollideMask::all_off();
+
+  // Note that this copy constructor is not used by the PandaNode copy
+  // constructor!  Any elements that must be copied between nodes
+  // should also be explicitly copied there.
 }
 
 ////////////////////////////////////////////////////////////////////

panda/src/pgraph/pandaNode.cxx

@@ -380,7 +380,10 @@ PandaNode(const PandaNode &copy) :
   cdata->_state = copy_cdata->_state;
   cdata->_effects = copy_cdata->_effects;
   cdata->_transform = copy_cdata->_transform;
+  cdata->_prev_transform = copy_cdata->_prev_transform;
+  cdata->_tag_data = copy_cdata->_tag_data;
   cdata->_draw_mask = copy_cdata->_draw_mask;
+  cdata->_fixed_internal_bound = copy_cdata->_fixed_internal_bound;
 }
 
 ////////////////////////////////////////////////////////////////////