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Merge pull request #6177

ef8dfe4 Prevent block.nTime from decreasing (Mark Friedenbach)
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laanwj committed Aug 6, 2015
2 parents 149f96c + ef8dfe4 commit 2f746c6e8a5d10fa2d432de9b43b694f40d5f4a1
Showing with 12 additions and 4 deletions.
  1. +11 −3 src/miner.cpp
  2. +1 −1 src/miner.h
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@@ -84,13 +84,19 @@ class TxPriorityCompare
}
};
-void UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev)
+int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev)
{
- pblock->nTime = std::max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
+ int64_t nOldTime = pblock->nTime;
+ int64_t nNewTime = std::max(pindexPrev->GetMedianTimePast()+1, GetAdjustedTime());
+
+ if (nOldTime < nNewTime)
+ pblock->nTime = nNewTime;
// Updating time can change work required on testnet:
if (consensusParams.fPowAllowMinDifficultyBlocks)
pblock->nBits = GetNextWorkRequired(pindexPrev, pblock, consensusParams);
+
+ return nNewTime - nOldTime;
}
CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn)
@@ -521,7 +527,9 @@ void static BitcoinMiner(const CChainParams& chainparams)
break;
// Update nTime every few seconds
- UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev);
+ if (UpdateTime(pblock, chainparams.GetConsensus(), pindexPrev) < 0)
+ break; // Recreate the block if the clock has run backwards,
+ // so that we can use the correct time.
if (chainparams.GetConsensus().fPowAllowMinDifficultyBlocks)
{
// Changing pblock->nTime can change work required on testnet:
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@@ -30,6 +30,6 @@ void GenerateBitcoins(bool fGenerate, int nThreads, const CChainParams& chainpar
CBlockTemplate* CreateNewBlock(const CScript& scriptPubKeyIn);
/** Modify the extranonce in a block */
void IncrementExtraNonce(CBlock* pblock, CBlockIndex* pindexPrev, unsigned int& nExtraNonce);
-void UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev);
+int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev);
#endif // BITCOIN_MINER_H

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