merge revision(s) 44880: [Backport #9477]

	* lib/resolv.rb: Ignore name servers which cause EAFNOSUPPORT on
	  socket creation.
	  Reported by Bjoern Rennhak.  [ruby-core:60442] [Bug #9477]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_9_3@44949 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 12 insertions, 4 deletions

diff --git a/lib/resolv.rb b/lib/resolv.rb
index 643532b905..9524703be4 100644
--- a/lib/resolv.rb
+++ b/lib/resolv.rb
@@ -500,8 +500,9 @@ class Resolv
           msg.rd = 1
           msg.add_question(candidate, typeclass)
           unless sender = senders[[candidate, nameserver, port]]
-            sender = senders[[candidate, nameserver, port]] =
-              requester.sender(msg, candidate, nameserver, port)
+            sender = requester.sender(msg, candidate, nameserver, port)
+            next if !sender
+            senders[[candidate, nameserver, port]] = sender
           end
           reply, reply_name = requester.request(sender, tout)
           case reply.rcode
@@ -707,7 +708,11 @@ class Resolv
               af = Socket::AF_INET
             end
             next if @socks_hash[bind_host]
-            sock = UDPSocket.new(af)
+            begin
+              sock = UDPSocket.new(af)
+            rescue Errno::EAFNOSUPPORT
+              next # The kernel doesn't support the address family.
+            end
             sock.do_not_reverse_lookup = true
             sock.fcntl(Fcntl::F_SETFD, Fcntl::FD_CLOEXEC) if defined? Fcntl::F_SETFD
             DNS.bind_random_port(sock, bind_host)
@@ -722,11 +727,12 @@ class Resolv
         end
 
         def sender(msg, data, host, port=Port)
+          sock = @socks_hash[host.index(':') ? "::" : "0.0.0.0"]
+          return nil if !sock
           service = [host, port]
           id = DNS.allocate_request_id(host, port)
           request = msg.encode
           request[0,2] = [id].pack('n')
-          sock = @socks_hash[host.index(':') ? "::" : "0.0.0.0"]
           return @senders[[service, id]] =
             Sender.new(request, data, sock, host, port)
         end
@@ -747,6 +753,7 @@ class Resolv
           attr_reader :data
 
           def send
+            raise "@sock is nil." if @sock.nil?
             @sock.send(@msg, 0, @host, @port)
           end
         end
@@ -790,6 +797,7 @@ class Resolv
 
         class Sender < Requester::Sender # :nodoc:
           def send
+            raise "@sock is nil." if @sock.nil?
             @sock.send(@msg, 0)
           end
           attr_reader :data