* lib/resolv.rb (Resolv::DNS#each_address): don't query IPv6 address

if the host has no global IPv6 address.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@21921 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Sat Jan 31 22:38:46 2009  Tanaka Akira  <akr@fsij.org>
+
+	* lib/resolv.rb (Resolv::DNS#each_address): don't query IPv6 address
+	  if the host has no global IPv6 address.
+
 Sat Jan 31 22:29:05 2009  Tanaka Akira  <akr@fsij.org>
 
 	* include/ruby/ruby.h (STR2CSTR): removed.

lib/resolv.rb

@@ -379,9 +379,21 @@ class Resolv
 
     def each_address(name)
       each_resource(name, Resource::IN::A) {|resource| yield resource.address}
-      each_resource(name, Resource::IN::AAAA) {|resource| yield resource.address}
+      if use_ipv6?
+        each_resource(name, Resource::IN::AAAA) {|resource| yield resource.address}
+      end
     end
 
+    def use_ipv6?
+      begin
+        list = Socket.ip_address_list
+      rescue NotImplementedError
+        return true
+      end
+      list.any? {|a| a.ipv6? && !a.ipv6_loopback? && !a.ipv6_linklocal? }
+    end
+    private :use_ipv6?
+
     ##
     # Gets the hostname for +address+ from the DNS resolver.
     #