message: Coinstake transaction valid only in block
diff: @@ -614,6 +614,10 @@ bool AcceptToMemoryPoolWorker(CTxMemPool& pool, CValidationState& state, const C
  if (tx.IsCoinBase())
  return state.DoS(100, false, REJECT_INVALID, "coinbase");
  + // ppcoin: coinstake is also only valid in a block, not as a loose transaction
  + if (tx.IsCoinStake())
  + return state.DoS(100, false, REJECT_INVALID, "coinstake");
  +
  // Reject transactions with witness before segregated witness activates (override with -prematurewitness)
  bool witnessEnabled = IsWitnessEnabled(chainActive.Tip(), Params().GetConsensus());
  if (!GetBoolArg("-prematurewitness",false) && tx.HasWitness() && !witnessEnabled) {
  