rc.library: support ipv4 mapped addresses

etc/rc.d/rc.library.source

@@ -81,9 +81,8 @@ min6() {
   [[ -n $1 ]] && read a m < <(IFS=/; echo $1) || return
   [[ $a == *"$f"* && $a == *'.'* ]] && b=${a#*$f} a=${a%$f*}$f || b=
   a=:$(for q in ${a//:/ }; do printf "$d%x" "0x$q"; d=:; done)
-  a=${a/$(grep -Po ':(0(:|$)){2,8}' <<< $a|sort|tail -1)/-}
-  [[ ${a:0:1} == : ]] && a=${a:1}
-  a=${a/-/::}
+  a=${a/$(grep -Po ':(0(:|$)){2,8}' <<< $a|sort|tail -1)/::}
+  [[ ${a:0:2} != :: ]] && a=${a:1}
   [[ -n $b ]] && a=${a%$f*}:$b
   [[ -z $m ]] && echo $a || echo $a/$m
 }