message: Prevent an unnecessary copy. Just use the map element directly.
diff: @@ -462,19 +462,16 @@ bool CGrapheneBlock::process(CNode *pfrom,
  LOCK(orphanpool.cs);
  for (auto &kv : orphanpool.mapOrphanTransactions)
  {
  - uint256 hash = kv.first;
  -
  - uint64_t cheapHash = hash.GetCheapHash();
  + uint64_t cheapHash = kv.first.GetCheapHash();
  if (mapPartialTxHash.count(cheapHash)) // Check for collisions
  collision = true;
  - mapPartialTxHash[cheapHash] = hash;
  + mapPartialTxHash[cheapHash] = kv.first;
  }
  // We don't have to keep the lock on mempool.cs here to do mempool.queryHashes
  // but we take the lock anyway so we don't have to re-lock again later.
  - ////////////////////// What is cs_xval for?
  LOCK(cs_xval);
  mempool.queryHashes(memPoolHashes);
  