UDB_FREE_CHUNK
UDB_FREE_CHUNK(fp->prev)->next = fp->next;
UDB_FREE_CHUNK(fp->next)->prev = fp->prev;
udb_free_chunk_d* fp = UDB_FREE_CHUNK(f);
UDB_FREE_CHUNK(fp->next)->prev = 0;
udb_free_chunk_d* fp = UDB_FREE_CHUNK(f);
UDB_FREE_CHUNK(fp->next)->prev = f;
udb_free_chunk_d* fp = UDB_FREE_CHUNK(f);
UDB_FREE_CHUNK(fp->next)->prev = f;
assert(UDB_FREE_CHUNK(other)->exp == (uint8_t)exp);
udb_free_chunk_d* cp = UDB_FREE_CHUNK(c);
UDB_FREE_CHUNK(cp->next)->prev = c;
udb_free_chunk_d* fp = UDB_FREE_CHUNK(chunk);