+/* Like host_nmtoa() but: ipv6-only, canonical output, no mask
+
+Arguments:
+ binary points to the ints
+ buffer big enough to hold the result
+
+Returns: the number of characters placed in buffer, not counting
+ the final nul.
+*/
+
+int
+ipv6_nmtoa(int * binary, uschar * buffer)
+{
+int i, j, k;
+uschar * c = buffer;
+uschar * d;
+
+for (i = 0; i < 4; i++)
+ { /* expand to text */
+ j = binary[i];
+ c += sprintf(CS c, "%x:%x:", (j >> 16) & 0xffff, j & 0xffff);
+ }
+
+for (c = buffer, k = -1, i = 0; i < 8; i++)
+ { /* find longest 0-group sequence */
+ if (*c == '0') /* must be "0:" */
+ {
+ uschar * s = c;
+ j = i;
+ while (c[2] == '0') i++, c += 2;
+ if (i-j > k)
+ {
+ k = i-j; /* length of sequence */
+ d = s; /* start of sequence */
+ }
+ }
+ while (*++c != ':') ;
+ c++;
+ }
+
+c[-1] = '\0'; /* drop trailing colon */
+
+/* debug_printf("%s: D k %d <%s> <%s>\n", __FUNCTION__, k, d, d + 2*(k+1)); */
+if (k >= 0)
+ { /* collapse */
+ c = d + 2*(k+1);
+ if (d == buffer) c--; /* need extra colon */
+ *d++ = ':'; /* 1st 0 */
+ while (*d++ = *c++) ;
+ }
+else
+ d = c;
+
+return d - buffer;
+}
+
+