- /* Do not mark the parents. The pointers in the mutable
- property list form two tree like structures (one for X
- relations, one for Y relations). Marking these can be done
- in limited stack space. If we add the parents, we will jump
- between X and Y in an erratic manner, leading to much more
- recursion depth (and core dumps if we link to pthreads). */
- }
-
- if (s->original_)
- scm_gc_mark (s->original_->self_scm ());