Sync changes from Dogecoin 1.10

5 files changed, 38 insertions, 5 deletions

diff --git a/src/dogecoin.cpp b/src/dogecoin.cpp
index 7e9281a4d..396c4cbc4 100644
--- a/src/dogecoin.cpp
+++ b/src/dogecoin.cpp
@@ -17,6 +17,24 @@ int static generateMTRandom(unsigned int s, int range)
     return dist(gen);
 }
 
+// Dogecoin: Normally minimum difficulty blocks can only occur in between
+// retarget blocks. However, once we introduce Digishield every block is
+// a retarget, so we need to handle minimum difficulty on all blocks.
+bool AllowDigishieldMinDifficultyForBlock(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params)
+{
+    // check if the chain allows minimum difficulty blocks
+    if (!params.fPowAllowMinDifficultyBlocks)
+        return false;
+
+    // check if the chain allows minimum difficulty blocks on recalc blocks
+    if (pindexLast->nHeight < 157500)
+    // if (!params.fPowAllowDigishieldMinDifficultyBlocks)
+        return false;
+
+    // Allow for a minimum block time if the elapsed time > 2*nTargetSpacing
+    return (pblock->GetBlockTime() > pindexLast->GetBlockTime() + params.nPowTargetSpacing*2);
+}
+
 unsigned int CalculateDogecoinNextWorkRequired(const CBlockIndex* pindexLast, int64_t nFirstBlockTime, const Consensus::Params& params)
 {
     int nHeight = pindexLast->nHeight + 1;
@@ -90,8 +108,7 @@ bool CheckAuxPowProofOfWork(const CBlockHeader& block, const Consensus::Params&
                      params.nAuxpowChainId, block.nVersion);
 
     /* If there is no auxpow, just check the block hash.  */
-    if (!block.auxpow)
-    {
+    if (!block.auxpow) {
         if (block.IsAuxpow())
             return error("%s : no auxpow on block with auxpow version",
                          __func__);
diff --git a/src/dogecoin.h b/src/dogecoin.h
index 1adbc1925..403673da5 100644
--- a/src/dogecoin.h
+++ b/src/dogecoin.h
@@ -6,6 +6,7 @@
 #include "chain.h"
 #include "chainparams.h"
 
+bool AllowDigishieldMinDifficultyForBlock(const CBlockIndex* pindexLast, const CBlockHeader *pblock, const Consensus::Params& params);
 CAmount GetDogecoinBlockSubsidy(int nHeight, const Consensus::Params& consensusParams, uint256 prevHash);
 unsigned int CalculateDogecoinNextWorkRequired(const CBlockIndex* pindexLast, int64_t nLastRetargetTime, const Consensus::Params& params);
 
diff --git a/src/pow.cpp b/src/pow.cpp
index 8996b3b58..220dcba63 100644
--- a/src/pow.cpp
+++ b/src/pow.cpp
@@ -18,8 +18,21 @@ unsigned int GetNextWorkRequired(const CBlockIndex* pindexLast, const CBlockHead
     assert(pindexLast != nullptr);
     unsigned int nProofOfWorkLimit = UintToArith256(params.powLimit).GetCompact();
 
+    // Dogecoin: Special rules for minimum difficulty blocks with Digishield
+    if (AllowDigishieldMinDifficultyForBlock(pindexLast, pblock, params))
+    {
+        // Special difficulty rule for testnet:
+        // If the new block's timestamp is more than 2* nTargetSpacing minutes
+        // then allow mining of a min-difficulty block.
+        return nProofOfWorkLimit;
+    }
+
     // Only change once per difficulty adjustment interval
-    if ((pindexLast->nHeight+1) % params.DifficultyAdjustmentInterval() != 0)
+    bool fNewDifficultyProtocol = (pindexLast->nHeight >= 145000);
+    const int64_t difficultyAdjustmentInterval = fNewDifficultyProtocol
+                                                 ? 1
+                                                 : params.DifficultyAdjustmentInterval();
+    if ((pindexLast->nHeight+1) % difficultyAdjustmentInterval != 0)
     {
         if (params.fPowAllowMinDifficultyBlocks)
         {
diff --git a/src/qt/test/addressbooktests.cpp b/src/qt/test/addressbooktests.cpp
index 352584604..6760b0786 100644
--- a/src/qt/test/addressbooktests.cpp
+++ b/src/qt/test/addressbooktests.cpp
@@ -56,7 +56,7 @@ void EditAddressAndSubmit(
  */
 void TestAddAddressesToSendBook()
 {
-    TestChain100Setup test;
+    TestChain240Setup test;
     std::shared_ptr<CWallet> wallet = std::make_shared<CWallet>("mock", WalletDatabase::CreateMock());
     bool firstRun;
     wallet->LoadWallet(firstRun);
diff --git a/src/test/auxpow_tests.cpp b/src/test/auxpow_tests.cpp
index ce9954fe6..6447ef9fd 100644
--- a/src/test/auxpow_tests.cpp
+++ b/src/test/auxpow_tests.cpp
@@ -414,7 +414,9 @@ BOOST_FIXTURE_TEST_CASE (auxpow_pow, BasicTestingSetup)
     mineBlock(block, true);
     BOOST_CHECK(CheckAuxPowProofOfWork(block, params));
 
-    block.nVersion = 2;
+    // Dogecoin block version 2 can be both AuxPoW and regular, so test 3
+
+    block.nVersion = 3;
     mineBlock(block, true);
     BOOST_CHECK(!CheckAuxPowProofOfWork(block, params));