ib->t = t;
ib->nodes = (struct avlnode *)((unsigned char *)ib->nodes + diff);
ib->roots = (off_t *)((unsigned char *)ib->roots + diff);
- ib->currroot = (struct avlnode *)((unsigned char *)ib->currroot + diff);
+ if (ib->currroot)
+ ib->currroot = (struct avlnode *)
+ ((unsigned char *)ib->currroot + diff);
ib->firstmutable = (struct avlnode *)((unsigned char *)ib->firstmutable + diff);
}