if ((ins = WT_SKIP_LAST(ins_head)) == NULL)
        return (0);
key.data = WT_INSERT_KEY(ins);
key.size = WT_INSERT_KEY_SIZE(ins);

WT_RET(__wt_compare(session, collator, srch_key, &key, &cmp));
if (cmp >= 0) {
        /*
         * !!!
         * We may race with another appending thread.
         *
         * To catch that case, rely on the atomic pointer read above
         * and set the next stack to NULL here.  If we have raced with
         * another thread, one of the next pointers will not be NULL by
         * the time they are checked against the next stack inside the
         * serialized insert function.
         */
        for (i = WT_SKIP_MAXDEPTH - 1; i >= 0; i--) {
                cbt->ins_stack[i] = (i == 0) ? &ins->next[0] :
                    (ins_head->tail[i] != NULL) ?
                    &ins_head->tail[i]->next[i] : &ins_head->head[i];
                cbt->next_stack[i] = NULL;
        }
        cbt->compare = -cmp;
        cbt->ins = ins;
        cbt->ins_head = ins_head;
        *donep = 1;
}