RUBY-398 skip seed node if neither primary nor secondary

lib/mongo/util/node.rb

@@ -166,12 +166,16 @@ module Mongo
       [host, port]
     end
 
-    # Ensure that this node is a member of a replica set.
+    # Ensure that this node is a healty member of a replica set.
     def check_set_membership(config)
       if !config['hosts']
         message = "Will not connect to #{host_string} because it's not a member " +
           "of a replica set."
         raise ConnectionFailure, message
+      elsif config['hosts'].length == 1 && !config['ismaster'] &&
+        !config['secondary']
+        message = "Attempting to connect to an unhealthy, single-node replica set."
+        raise ConnectionFailure, message
       end
     end
 

test/replica_sets/complex_connect_test.rb

@@ -1,4 +1,5 @@
 $:.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
+require 'logger'
 require './test/replica_sets/rs_test_helper'
 
 class ComplexConnectTest < Test::Unit::TestCase
@@ -10,10 +11,11 @@ class ComplexConnectTest < Test::Unit::TestCase
   end
 
   def test_complex_connect
+    logger = Logger.new(STDOUT)
     primary = Connection.new(self.rs.host, self.rs.ports[0])
 
     @conn = ReplSetConnection.new([self.rs.host, self.rs.ports[2]], [self.rs.host, self.rs.ports[1]],
-      [self.rs.host, self.rs.ports[0]])
+      [self.rs.host, self.rs.ports[0]], :logger => logger)
 
     @conn['test']['foo'].insert({:a => 1})
     assert @conn['test']['foo'].find_one