* 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

1 files changed, 13 insertions, 1 deletions

diff --git a/lib/resolv.rb b/lib/resolv.rb
index fc3c78215b..ab10a79d72 100644
--- a/lib/resolv.rb
+++ b/lib/resolv.rb
@@ -379,8 +379,20 @@ 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.