+ char *dend, *dbegin = dest;
+ int len = -1, i, j;
+ if (p==end || space <= 0) return -1;
+ dend = dest + (space > 254 ? 254 : space);
+ /* detect reference loop using an iteration counter */
+ for (i=0; i < end-base; i+=2) {
+ /* loop invariants: p<end, dest<dend */