Merge pull request bitcoin#3 from bitcoin-unlimited/dev_parallel

Unsolved block's height is improperly updated by chain tip height

src/main.cpp

@@ -3888,9 +3888,13 @@ bool ContextualCheckBlock(const CBlock& block, CValidationState& state, CBlockIn
     {
         CScript expect = CScript() << nHeight;
         if (block.vtx[0].vin[0].scriptSig.size() < expect.size() ||
-            !std::equal(expect.begin(), expect.end(), block.vtx[0].vin[0].scriptSig.begin())) {
-            return state.DoS(100, error("%s: block height mismatch in coinbase", __func__), REJECT_INVALID, "bad-cb-height");
-        }
+            !std::equal(expect.begin(), expect.end(), block.vtx[0].vin[0].scriptSig.begin()))
+          {
+            int blockCoinbaseHeight = block.GetHeight();
+            uint256 hashp = block.hashPrevBlock;
+            uint256 hash = block.GetHash();
+            return state.DoS(100, error("%s: block height mismatch in coinbase, expected %d, got %d, block is %s, parent block is %s, pprev is %s", __func__,nHeight,blockCoinbaseHeight,hash.ToString(),hashp.ToString(), pindexPrev->phashBlock->ToString()), REJECT_INVALID, "bad-cb-height");
+          }
     }
 
     return true;

src/miner.cpp

@@ -179,7 +179,10 @@ CBlockTemplate* CreateNewBlock(const CChainParams& chainparams, const CScript& s
         LOCK2(cs_main, mempool.cs);
         CBlockIndex* pindexPrev = chainActive.Tip();
         const int nHeight = pindexPrev->nHeight + 1;
-        pblock->nTime = GetAdjustedTime();
+        // Fill in header
+        pblock->hashPrevBlock  = pindexPrev->GetBlockHash();
+        pblock->nBits          = GetNextWorkRequired(pindexPrev, pblock, chainparams.GetConsensus());        
+        pblock->nTime          = GetAdjustedTime();
         const int64_t nMedianTimePast = pindexPrev->GetMedianTimePast();
 
         pblock->nVersion = UnlimitedComputeBlockVersion(pindexPrev, chainparams.GetConsensus(),pblock->nTime);
@@ -361,11 +364,7 @@ CBlockTemplate* CreateNewBlock(const CChainParams& chainparams, const CScript& s
 
         pblock->vtx[0] = txNew;
         pblocktemplate->vTxFees[0] = -nFees;
-
-        // Fill in header
-        pblock->hashPrevBlock  = pindexPrev->GetBlockHash();
         UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev);
-        pblock->nBits          = GetNextWorkRequired(pindexPrev, pblock, chainparams.GetConsensus());
         pblock->nNonce         = 0;
         pblocktemplate->vTxSigOps[0] = GetLegacySigOpCount(pblock->vtx[0]);
 
@@ -392,7 +391,7 @@ CBlockTemplate* CreateNewBlock(const CChainParams& chainparams, const CScript& s
     return pblocktemplate.release();
 }
 
-void IncrementExtraNonce(CBlock* pblock, const CBlockIndex* pindexPrev, unsigned int& nExtraNonce)
+void IncrementExtraNonce(CBlock* pblock, unsigned int& nExtraNonce)
 {
     // Update nExtraNonce
     static uint256 hashPrevBlock;
@@ -402,7 +401,7 @@ void IncrementExtraNonce(CBlock* pblock, const CBlockIndex* pindexPrev, unsigned
         hashPrevBlock = pblock->hashPrevBlock;
     }
     ++nExtraNonce;
-    unsigned int nHeight = pindexPrev->nHeight+1; // Height first in coinbase required for block.version=2
+    unsigned int nHeight = pblock->GetHeight(); // Height first in coinbase required for block.version=2
     CMutableTransaction txCoinbase(pblock->vtx[0]);
 
     CScript script = (CScript() << nHeight << CScriptNum(nExtraNonce));

src/miner.h

@@ -30,7 +30,7 @@ struct CBlockTemplate
 /** Generate a new block, without valid proof-of-work */
 CBlockTemplate* CreateNewBlock(const CChainParams& chainparams, const CScript& scriptPubKeyIn);
 /** Modify the extranonce in a block */
-void IncrementExtraNonce(CBlock* pblock, const CBlockIndex* pindexPrev, unsigned int& nExtraNonce);
+void IncrementExtraNonce(CBlock* pblock, unsigned int& nExtraNonce);
 int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev);
 
 #endif // BITCOIN_MINER_H

src/primitives/block.h

@@ -122,6 +122,18 @@ class CBlock : public CBlockHeader
         READWRITE(vtx);
     }
 
+    uint64_t GetHeight() const  // Returns the block's height as specified in its coinbase transaction
+    {
+      const CScript& sig = vtx[0].vin[0].scriptSig;
+      int numlen = sig[0];
+      if (numlen == OP_0) return 0;
+      if ((numlen >= OP_1) && (numlen <= OP_16)) return numlen-OP_1+1;
+      std::vector<unsigned char> heightScript(numlen);
+      copy(sig.begin()+1, sig.begin()+1+numlen,heightScript.begin());
+      CScriptNum coinbaseHeight(heightScript, false,numlen);
+      return coinbaseHeight.getint();
+    }
+
     void SetNull()
     {
         CBlockHeader::SetNull();

src/rpc/mining.cpp

@@ -119,8 +119,8 @@ UniValue generateBlocks(boost::shared_ptr<CReserveScript> coinbaseScript, int nG
             throw JSONRPCError(RPC_INTERNAL_ERROR, "Couldn't create new block");
         CBlock *pblock = &pblocktemplate->block;
         {
-            LOCK(cs_main);
-            IncrementExtraNonce(pblock, chainActive.Tip(), nExtraNonce);
+          // LOCK(cs_main);
+            IncrementExtraNonce(pblock, nExtraNonce);
         }
         while (nMaxTries > 0 && pblock->nNonce < nInnerLoopCount && !CheckProofOfWork(pblock->GetHash(), pblock->nBits, Params().GetConsensus())) {
             ++pblock->nNonce;
@@ -525,9 +525,9 @@ UniValue getblocktemplate(const UniValue& params, bool fHelp)
     }
 
     // Update block
-    static CBlockIndex* pindexPrev;
-    static int64_t nStart;
-    static CBlockTemplate* pblocktemplate;
+    static CBlockIndex* pindexPrev = NULL;
+    static int64_t nStart = 0;
+    static CBlockTemplate* pblocktemplate = NULL;
     if (pindexPrev != chainActive.Tip() ||
         (mempool.GetTransactionsUpdated() != nTransactionsUpdatedLast && GetTime() - nStart > 5))
     {
@@ -674,7 +674,7 @@ UniValue getblocktemplate(const UniValue& params, bool fHelp)
     result.push_back(Pair("sizelimit", (int64_t)maxGeneratedBlock));
     result.push_back(Pair("curtime", pblock->GetBlockTime()));
     result.push_back(Pair("bits", strprintf("%08x", pblock->nBits)));
-    result.push_back(Pair("height", (int64_t)(pindexPrev->nHeight+1)));
+    result.push_back(Pair("height", (int64_t)(pblock->GetHeight()))); // BU get the height directly from the block because pindexPrev could change if another block has come in.
 
     return result;
 }

src/test/test_bitcoin.cpp

@@ -109,7 +109,7 @@ TestChain100Setup::CreateAndProcessBlock(const std::vector<CMutableTransaction>&
         block.vtx.push_back(tx);
     // IncrementExtraNonce creates a valid coinbase and merkleRoot
     unsigned int extraNonce = 0;
-    IncrementExtraNonce(&block, chainActive.Tip(), extraNonce);
+    IncrementExtraNonce(&block, extraNonce);
 
     while (!CheckProofOfWork(block.GetHash(), block.nBits, chainparams.GetConsensus())) ++block.nNonce;
 

src/unlimited.cpp

@@ -807,7 +807,7 @@ void static BitcoinMiner(const CChainParams& chainparams)
                 return;
             }
             CBlock *pblock = &pblocktemplate->block;
-            IncrementExtraNonce(pblock, pindexPrev, nExtraNonce);
+            IncrementExtraNonce(pblock, nExtraNonce);
 
             LogPrintf("Running BitcoinMiner with %u transactions in block (%u bytes)\n", pblock->vtx.size(),
                 ::GetSerializeSize(*pblock, SER_NETWORK, PROTOCOL_VERSION));