message: Fixed edge case in spend verification check
diff: @@ -121,6 +121,7 @@ bool CheckSpendZcoinTransaction(const CTransaction &tx,
  // Build vector of coins sorted by the time of mint
  index = coinGroup.lastBlock;
  vector<CBigNum> pubCoins = index->mintedPubCoins[denominationAndId];
  + if (index != coinGroup.firstBlock) {
  do {
  index = index->pprev;
  if (index->mintedPubCoins.count(denominationAndId) > 0)
  @@ -128,6 +129,7 @@ bool CheckSpendZcoinTransaction(const CTransaction &tx,
  index->mintedPubCoins[denominationAndId].cbegin(),
  index->mintedPubCoins[denominationAndId].cend());
  } while (index != coinGroup.firstBlock);
  + }
  libzerocoin::Accumulator accumulator(ZCParams, targetDenomination);
  BOOST_FOREACH(const CBigNum &pubCoin, pubCoins) {
  