Merge #16060: Bury bip9 deployments

e78aaf41f43d0e2ad78fa6d8dad61032c8ef73d0 [docs] Add release notes for burying bip 9 soft fork deployments (John Newbery)
8319e738f9f118025b332e4fa804d4c31e4113f4 [tests] Add coverage for the content of getblockchaininfo.softforks (James O'Beirne)
0328dcdcfcb56dc8918697716d7686be048ad0b3 [Consensus] Bury segwit deployment (John Newbery)
1c93b9b31c2ab7358f9d55f52dd46340397c906d [Consensus] Bury CSV deployment height (John Newbery)
3862e473f0cb71a762c0306b171b591341d58142 [rpc] Tidy up reporting of buried and ongoing softforks (John Newbery)

Pull request description:

  This hardcodes CSV and segwit activation heights, similar to the BIP 90 buried deployments for BIPs 34, 65 and 66.

  CSV and segwit have been active for over 18 months. Hardcoding the activation height is a code simplification, makes it easier to understand segwit activation status, and reduces technical debt.

  This was originally attempted by jl2012 in #11398 and again by me in #12360.

ACKs for top commit:
  ajtowns:
    ACK e78aaf41f43d0e2ad78fa6d8dad61032c8ef73d0 ; checked diff to previous acked commit, checked tests still work
  ariard:
    ACK e78aaf4, check diff, run the tests again and successfully activated csv/segwit heights on mainnet as expected.
  MarcoFalke:
    ACK e78aaf41f43d0e2ad78fa6d8dad61032c8ef73d0 (still didn't check if the mainnet block heights are correct, but the code looks good now)

Tree-SHA512: 7e951829106e21a81725f7d3e236eddbb59349189740907bb47e33f5dbf95c43753ac1231f47ae7bee85c8c81b2146afcdfdc11deb1503947f23093a9c399912

1 files changed, 13 insertions, 18 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index 8f44e2565a..74f68a3047 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1648,7 +1648,7 @@ static ThresholdConditionCache warningcache[VERSIONBITS_NUM_BITS] GUARDED_BY(cs_
 // environment. See test/functional/p2p-segwit.py.
 static bool IsScriptWitnessEnabled(const Consensus::Params& params)
 {
-    return params.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nTimeout != 0;
+    return params.SegwitHeight != std::numeric_limits<int>::max();
 }
 
 static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consensus::Params& consensusparams) EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
@@ -1684,12 +1684,13 @@ static unsigned int GetBlockScriptFlags(const CBlockIndex* pindex, const Consens
         flags |= SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY;
     }
 
-    // Start enforcing BIP68 (sequence locks) and BIP112 (CHECKSEQUENCEVERIFY) using versionbits logic.
-    if (VersionBitsState(pindex->pprev, consensusparams, Consensus::DEPLOYMENT_CSV, versionbitscache) == ThresholdState::ACTIVE) {
+    // Start enforcing BIP112 (CHECKSEQUENCEVERIFY)
+    if (pindex->nHeight >= consensusparams.CSVHeight) {
         flags |= SCRIPT_VERIFY_CHECKSEQUENCEVERIFY;
     }
 
-    if (IsNullDummyEnabled(pindex->pprev, consensusparams)) {
+    // Start enforcing BIP147 NULLDUMMY (activated simultaneously with segwit)
+    if (IsWitnessEnabled(pindex->pprev, consensusparams)) {
         flags |= SCRIPT_VERIFY_NULLDUMMY;
     }
 
@@ -1874,9 +1875,9 @@ bool CChainState::ConnectBlock(const CBlock& block, CValidationState& state, CBl
         }
     }
 
-    // Start enforcing BIP68 (sequence locks) and BIP112 (CHECKSEQUENCEVERIFY) using versionbits logic.
+    // Start enforcing BIP68 (sequence locks)
     int nLockTimeFlags = 0;
-    if (VersionBitsState(pindex->pprev, chainparams.GetConsensus(), Consensus::DEPLOYMENT_CSV, versionbitscache) == ThresholdState::ACTIVE) {
+    if (pindex->nHeight >= chainparams.GetConsensus().CSVHeight) {
         nLockTimeFlags |= LOCKTIME_VERIFY_SEQUENCE;
     }
 
@@ -3088,14 +3089,8 @@ bool CheckBlock(const CBlock& block, CValidationState& state, const Consensus::P
 
 bool IsWitnessEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& params)
 {
-    LOCK(cs_main);
-    return (VersionBitsState(pindexPrev, params, Consensus::DEPLOYMENT_SEGWIT, versionbitscache) == ThresholdState::ACTIVE);
-}
-
-bool IsNullDummyEnabled(const CBlockIndex* pindexPrev, const Consensus::Params& params)
-{
-    LOCK(cs_main);
-    return (VersionBitsState(pindexPrev, params, Consensus::DEPLOYMENT_SEGWIT, versionbitscache) == ThresholdState::ACTIVE);
+    int height = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1;
+    return (height >= params.SegwitHeight);
 }
 
 // Compute at which vout of the block's coinbase transaction the witness
@@ -3130,7 +3125,7 @@ std::vector<unsigned char> GenerateCoinbaseCommitment(CBlock& block, const CBloc
     std::vector<unsigned char> commitment;
     int commitpos = GetWitnessCommitmentIndex(block);
     std::vector<unsigned char> ret(32, 0x00);
-    if (consensusParams.vDeployments[Consensus::DEPLOYMENT_SEGWIT].nTimeout != 0) {
+    if (consensusParams.SegwitHeight != std::numeric_limits<int>::max()) {
         if (commitpos == -1) {
             uint256 witnessroot = BlockWitnessMerkleRoot(block, nullptr);
             CHash256().Write(witnessroot.begin(), 32).Write(ret.data(), 32).Finalize(witnessroot.begin());
@@ -3228,9 +3223,9 @@ static bool ContextualCheckBlock(const CBlock& block, CValidationState& state, c
 {
     const int nHeight = pindexPrev == nullptr ? 0 : pindexPrev->nHeight + 1;
 
-    // Start enforcing BIP113 (Median Time Past) using versionbits logic.
+    // Start enforcing BIP113 (Median Time Past).
     int nLockTimeFlags = 0;
-    if (VersionBitsState(pindexPrev, consensusParams, Consensus::DEPLOYMENT_CSV, versionbitscache) == ThresholdState::ACTIVE) {
+    if (nHeight >= consensusParams.CSVHeight) {
         assert(pindexPrev != nullptr);
         nLockTimeFlags |= LOCKTIME_MEDIAN_TIME_PAST;
     }
@@ -3265,7 +3260,7 @@ static bool ContextualCheckBlock(const CBlock& block, CValidationState& state, c
     //   {0xaa, 0x21, 0xa9, 0xed}, and the following 32 bytes are SHA256^2(witness root, witness reserved value). In case there are
     //   multiple, the last one is used.
     bool fHaveWitness = false;
-    if (VersionBitsState(pindexPrev, consensusParams, Consensus::DEPLOYMENT_SEGWIT, versionbitscache) == ThresholdState::ACTIVE) {
+    if (nHeight >= consensusParams.SegwitHeight) {
         int commitpos = GetWitnessCommitmentIndex(block);
         if (commitpos != -1) {
             bool malleated = false;