f'blockheaders include block height, nodes validate it'

Author: jtimon

src/chain.h

@@ -14,8 +14,6 @@
 
 #include <vector>
 
-#include <util.h>
-
 /**
  * Maximum amount of time that a block timestamp is allowed to exceed the
  * current network-adjusted time before the block will be accepted.
@@ -409,7 +407,9 @@ class CDiskBlockIndex : public CBlockIndex
         READWRITE(hashPrev);
         READWRITE(hashMerkleRoot);
         READWRITE(nTime);
-        READWRITE(block_height);
+        if (g_con_blockheightinheader) {
+            READWRITE(block_height);
+        }
         READWRITE(nBits);
         READWRITE(nNonce);
     }

src/chainparams.cpp

@@ -125,11 +125,7 @@ class CMainParams : public CChainParams {
 
         genesis = CreateGenesisBlock(1231006505, 2083236893, 0x1d00ffff, 1, 50 * COIN);
         consensus.hashGenesisBlock = genesis.GetHash();
-        consensus.blockheight_in_header = gArgs.GetBoolArg("-con_blockheightinheader", false);
-        // Serialization will not match if true
-        if (!consensus.blockheight_in_header) {
-            assert(consensus.hashGenesisBlock == uint256S("0x000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"));
-        }
+        assert(consensus.hashGenesisBlock == uint256S("0x000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"));
         assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));
 
         // Note that of those which support the service bits prefix, most only support a subset of
@@ -238,11 +234,7 @@ class CTestNetParams : public CChainParams {
 
         genesis = CreateGenesisBlock(1296688602, 414098458, 0x1d00ffff, 1, 50 * COIN);
         consensus.hashGenesisBlock = genesis.GetHash();
-        consensus.blockheight_in_header = gArgs.GetBoolArg("-con_blockheightinheader", false);
-        // Serialization will not match if true
-        if (!consensus.blockheight_in_header) {
-            assert(consensus.hashGenesisBlock == uint256S("0x000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943"));
-        }
+        assert(consensus.hashGenesisBlock == uint256S("0x000000000933ea01ad0ee984209779baaec3ced90fa3f408719526f8d77f4943"));
         assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));
 
         vFixedSeeds.clear();
@@ -333,11 +325,7 @@ class CRegTestParams : public CChainParams {
 
         genesis = CreateGenesisBlock(1296688602, 2, 0x207fffff, 1, 50 * COIN);
         consensus.hashGenesisBlock = genesis.GetHash();
-        consensus.blockheight_in_header = gArgs.GetBoolArg("-con_blockheightinheader", false);
-        // Serialization will not match if true
-        if (!consensus.blockheight_in_header) {
-            assert(consensus.hashGenesisBlock == uint256S("0x0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206"));
-        }
+        assert(consensus.hashGenesisBlock == uint256S("0x0f9188f13cb7b2c71f2a335e3a4fc328bf5beb436012afca590b1a11466e2206"));
         assert(genesis.hashMerkleRoot == uint256S("0x4a5e1e4baab89f3a32518a88c31bc87f618f76673e2cc77ab2127b7afdeda33b"));
 
         vFixedSeeds.clear(); //!< Regtest mode doesn't have any fixed seeds.
@@ -440,9 +428,9 @@ class CCustomParams : public CRegTestParams {
         consensus.nMinimumChainWork = uint256S(args.GetArg("-con_nminimumchainwork", "0x0"));
         consensus.defaultAssumeValid = uint256S(args.GetArg("-con_defaultassumevalid", "0x00"));
 
-        // Note: This gArg is accessed one more time in block.h for serialization to avoid
+        // Note: g_con_blockheightinheader is used instead of consensus.blockheight_in_header to avoid
         // circular dependency
-        consensus.blockheight_in_header = gArgs.GetBoolArg("-con_blockheightinheader", false);
+        consensus.blockheight_in_header = g_con_blockheightinheader = gArgs.GetBoolArg("-con_blockheightinheader", false);
 
         // All non-zero coinbase outputs must go to this scriptPubKey
         std::vector<unsigned char> man_bytes = ParseHex(gArgs.GetArg("-con_mandatorycoinbase", ""));

src/consensus/params.h

@@ -78,6 +78,7 @@ struct Params {
     int64_t DifficultyAdjustmentInterval() const { return nPowTargetTimespan / nPowTargetSpacing; }
     uint256 nMinimumChainWork;
     uint256 defaultAssumeValid;
+
     // Elements-specific chainparams
     CScript mandatory_coinbase_destination;
     bool blockheight_in_header;

src/miner.cpp

@@ -168,7 +168,7 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
     // Fill in header
     pblock->hashPrevBlock  = pindexPrev->GetBlockHash();
     UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev);
-    if (Params().GetConsensus().blockheight_in_header) {
+    if (g_con_blockheightinheader) {
         pblock->block_height = nHeight;
     }
     pblock->nBits          = GetNextWorkRequired(pindexPrev, pblock, chainparams.GetConsensus());

src/primitives/block.cpp

@@ -10,6 +10,8 @@
 #include <utilstrencodings.h>
 #include <crypto/common.h>
 
+bool g_con_blockheightinheader = false;
+
 uint256 CBlockHeader::GetHash() const
 {
     return SerializeHash(*this);

src/primitives/block.h

@@ -9,7 +9,11 @@
 #include <primitives/transaction.h>
 #include <serialize.h>
 #include <uint256.h>
-#include <util.h>
+
+/** 
+ * Also found in consensus params as blockheight_in_header (circular dep otherwise)
+ */
+extern bool g_con_blockheightinheader;
 
 /** Nodes collect new transactions into a block, hash them into a hash tree,
  * and scan through nonce values to make the block's hash satisfy proof-of-work
@@ -45,8 +49,7 @@ class CBlockHeader
         READWRITE(hashPrevBlock);
         READWRITE(hashMerkleRoot);
         READWRITE(nTime);
-        // Also found in consensus params as blockheight_in_header (circular dep otherwise)
-        if (gArgs.GetBoolArg("-con_blockheightinheader", false)) {
+        if (g_con_blockheightinheader) {
             READWRITE(block_height);
         }
         READWRITE(nBits);

src/validation.cpp

@@ -3264,7 +3264,7 @@ static bool ContextualCheckBlockHeader(const CBlockHeader& block, CValidationSta
         return state.Invalid(false, REJECT_INVALID, "time-too-old", "block's timestamp is too early");
 
     // Check height in header against prev
-    if (consensusParams.blockheight_in_header && (uint32_t)nHeight != block.block_height)
+    if (g_con_blockheightinheader && (uint32_t)nHeight != block.block_height)
         return state.Invalid(error("%s: block height in header is incorrect", __func__),
                              REJECT_INVALID, "bad-header-height");
 

test/functional/feature_genesishash.py

@@ -26,6 +26,15 @@
                 '-con_genesis_style=default_style',
         ],
     },
+
+    {
+        'memo': 'default_style with height in header',
+        'genesis': 'be878d13f0b4fd63c9e3d07c8a09a1f47f4a915e017a4648fff6bdfda751189e',
+        'args': [
+            '-con_genesis_style=default_style',
+            '-con_blockheightinheader',
+        ],
+    },
 ]
 
 class GenesisHashTest(BitcoinTestFramework):