new_contents: #!/usr/bin/env python2
  # Copyright (c) 2014 The Bitcoin Core developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #
  # Test InvalidateBlock code
  #
  
  from test_framework import BitcoinTestFramework
  from bitcoinrpc.authproxy import AuthServiceProxy, JSONRPCException
  from util import *
  
  class InvalidateTest(BitcoinTestFramework):
      
          
      def setup_chain(self):
          print("Initializing test directory "+self.options.tmpdir)
          initialize_chain_clean(self.options.tmpdir, 2)
                   
      def setup_network(self):
          self.nodes = []
          self.is_network_split = False 
          self.nodes.append(start_node(0, self.options.tmpdir, ["-debug"]))
          self.nodes.append(start_node(1, self.options.tmpdir, ["-debug"]))
          
      def run_test(self):
          print "Mine 4 blocks on Node 0"
          self.nodes[0].setgenerate(True, 4)
          assert(self.nodes[0].getblockcount() == 4)
          besthash = self.nodes[0].getbestblockhash()
  
          print "Mine competing 6 blocks on Node 1"
          self.nodes[1].setgenerate(True, 6)
          assert(self.nodes[1].getblockcount() == 6)
  
          print "Connect nodes to force a reorg"
          connect_nodes_bi(self.nodes,0,1)
          sync_blocks(self.nodes)
          assert(self.nodes[0].getblockcount() == 6)
          badhash = self.nodes[1].getblockhash(2)
  
          print "Invalidate block 2 on node 0 and verify we reorg to node 0's original chain"
          self.nodes[0].invalidateblock(badhash)
          newheight = self.nodes[0].getblockcount()
          newhash = self.nodes[0].getbestblockhash()
          if (newheight != 4 or newhash != besthash):
              raise AssertionError("Wrong tip for node0, hash %s, height %d"%(newhash,newheight))
  
  if __name__ == '__main__':
      InvalidateTest().main()
  
subject: add RPC test for InvalidateBlock