--- ipaddr.rb	2012-11-29 22:11:05.000000000 -0800
+++ ipaddrpatch.rb	2012-11-29 22:07:30.000000000 -0800
@@ -548,11 +548,15 @@
         addr = in_addr($~[4,4])
         left = $1
         right = $3 + '0:0'
-      else
+      elsif !($1 == "" or $2 == "")
         left.count(':') <= 7 or raise InvalidAddressError, "invalid address"
         left = $1
         right = $2
         addr = 0
+      else
+        left = $1 + $2
+        right = ""
+        addr = 0
       end
     else
       raise InvalidAddressError, "invalid address"