1 files changed, 12 insertions, 16 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index 09288be1ca..d7d880d24f 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -455,7 +455,7 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool
 
     // Reject transactions with witness before segregated witness activates (override with -prematurewitness)
     bool witnessEnabled = IsWitnessEnabled(chainActive.Tip(), chainparams.GetConsensus());
-    if (!GetBoolArg("-prematurewitness",false) && tx.HasWitness() && !witnessEnabled) {
+    if (!GetBoolArg("-prematurewitness", false) && tx.HasWitness() && !witnessEnabled) {
         return state.DoS(0, false, REJECT_NONSTANDARD, "no-witness-yet", true);
     }
 
@@ -532,24 +532,20 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool
         CCoinsViewMemPool viewMemPool(pcoinsTip, pool);
         view.SetBackend(viewMemPool);
 
-        // do we already have it?
-        for (size_t out = 0; out < tx.vout.size(); out++) {
-            COutPoint outpoint(hash, out);
-            bool had_coin_in_cache = pcoinsTip->HaveCoinInCache(outpoint);
-            if (view.HaveCoin(outpoint)) {
-                if (!had_coin_in_cache) {
-                    coins_to_uncache.push_back(outpoint);
-                }
-                return state.Invalid(false, REJECT_DUPLICATE, "txn-already-known");
-            }
-        }
-
         // do all inputs exist?
         for (const CTxIn txin : tx.vin) {
             if (!pcoinsTip->HaveCoinInCache(txin.prevout)) {
                 coins_to_uncache.push_back(txin.prevout);
             }
             if (!view.HaveCoin(txin.prevout)) {
+                // Are inputs missing because we already have the tx?
+                for (size_t out = 0; out < tx.vout.size(); out++) {
+                    // Optimistically just do efficient check of cache for outputs
+                    if (pcoinsTip->HaveCoinInCache(COutPoint(hash, out))) {
+                        return state.Invalid(false, REJECT_DUPLICATE, "txn-already-known");
+                    }
+                }
+                // Otherwise assume this might be an orphan tx for which we just haven't seen parents yet
                 if (pfMissingInputs) {
                     *pfMissingInputs = true;
                 }
@@ -1141,7 +1137,7 @@ static void CheckForkWarningConditionsOnNewFork(CBlockIndex* pindexNewForkTip)
     // or a chain that is entirely longer than ours and invalid (note that this should be detected by both)
     // We define it this way because it allows us to only store the highest fork tip (+ base) which meets
     // the 7-block condition and from this always have the most-likely-to-cause-warning fork
-    if (pfork && (!pindexBestForkTip || (pindexBestForkTip && pindexNewForkTip->nHeight > pindexBestForkTip->nHeight)) &&
+    if (pfork && (!pindexBestForkTip || pindexNewForkTip->nHeight > pindexBestForkTip->nHeight) &&
             pindexNewForkTip->nChainWork - pfork->nChainWork > (GetBlockProof(*pfork) * 7) &&
             chainActive.Height() - pindexNewForkTip->nHeight < 72)
     {
@@ -2803,7 +2799,7 @@ bool CheckBlock(const CBlock& block, CValidationState& state, const Consensus::P
     // checks that use witness data may be performed here.
 
     // Size limits
-    if (block.vtx.empty() || block.vtx.size() > MAX_BLOCK_BASE_SIZE || ::GetSerializeSize(block, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) > MAX_BLOCK_BASE_SIZE)
+    if (block.vtx.empty() || block.vtx.size() * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT || ::GetSerializeSize(block, SER_NETWORK, PROTOCOL_VERSION | SERIALIZE_TRANSACTION_NO_WITNESS) * WITNESS_SCALE_FACTOR > MAX_BLOCK_WEIGHT)
         return state.DoS(100, false, REJECT_INVALID, "bad-blk-length", false, "size limits failed");
 
     // First transaction must be coinbase, the rest must not be
@@ -2890,7 +2886,7 @@ std::vector<unsigned char> GenerateCoinbaseCommitment(CBlock& block, const CBloc
     if (consensusParams.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nTimeout != 0) {
         if (commitpos == -1) {
             uint256 witnessroot = BlockWitnessMerkleRoot(block, NULL);
-            CHash256().Write(witnessroot.begin(), 32).Write(&ret[0], 32).Finalize(witnessroot.begin());
+            CHash256().Write(witnessroot.begin(), 32).Write(ret.data(), 32).Finalize(witnessroot.begin());
             CTxOut out;
             out.nValue = 0;
             out.scriptPubKey.resize(38);