1 files changed, 44 insertions, 9 deletions

diff --git a/src/main.cpp b/src/main.cpp
index 26a22ae6f..9016fe42a 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -74,7 +74,7 @@ size_t nCoinCacheUsage = 5000 * 300;
 uint64_t nPruneTarget = 0;
 bool fAlerts = DEFAULT_ALERTS;
 
-/** Fees smaller than this (in satoshi) are considered zero fee (for relaying and mining) */
+/** Fees smaller than this (in satoshi) are considered zero fee (for relaying, mining and transaction creation) */
 CFeeRate minRelayTxFee = CFeeRate(1000);
 
 CTxMemPool mempool(::minRelayTxFee);
@@ -650,10 +650,35 @@ bool IsFinalTx(const CTransaction &tx, int nBlockHeight, int64_t nBlockTime)
     return true;
 }
 
-bool CheckFinalTx(const CTransaction &tx)
+bool CheckFinalTx(const CTransaction &tx, int flags)
 {
     AssertLockHeld(cs_main);
-    return IsFinalTx(tx, chainActive.Height() + 1, GetAdjustedTime());
+
+    // By convention a negative value for flags indicates that the
+    // current network-enforced consensus rules should be used. In
+    // a future soft-fork scenario that would mean checking which
+    // rules would be enforced for the next block and setting the
+    // appropriate flags. At the present time no soft-forks are
+    // scheduled, so no flags are set.
+    flags = std::max(flags, 0);
+
+    // CheckFinalTx() uses chainActive.Height()+1 to evaluate
+    // nLockTime because when IsFinalTx() is called within
+    // CBlock::AcceptBlock(), the height of the block *being*
+    // evaluated is what is used. Thus if we want to know if a
+    // transaction can be part of the *next* block, we need to call
+    // IsFinalTx() with one more than chainActive.Height().
+    const int nBlockHeight = chainActive.Height() + 1;
+
+    // Timestamps on the other hand don't get any special treatment,
+    // because we can't know what timestamp the next block will have,
+    // and there aren't timestamp applications where it matters.
+    // However this changes once median past time-locks are enforced:
+    const int64_t nBlockTime = (flags & LOCKTIME_MEDIAN_TIME_PAST)
+                             ? chainActive.Tip()->GetMedianTimePast()
+                             : GetAdjustedTime();
+
+    return IsFinalTx(tx, nBlockHeight, nBlockTime);
 }
 
 unsigned int GetLegacySigOpCount(const CTransaction& tx)
@@ -797,7 +822,7 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
     // Only accept nLockTime-using transactions that can be mined in the next
     // block; we don't want our mempool filled up with transactions that can't
     // be mined yet.
-    if (!CheckFinalTx(tx))
+    if (!CheckFinalTx(tx, STANDARD_LOCKTIME_VERIFY_FLAGS))
         return state.DoS(0, false, REJECT_NONSTANDARD, "non-final");
 
     // is it already in the memory pool?
@@ -2517,8 +2542,6 @@ bool FindBlockPos(CValidationState &state, CDiskBlockPos &pos, unsigned int nAdd
 
     if (!fKnown) {
         while (vinfoBlockFile[nFile].nSize + nAddSize >= MAX_BLOCKFILE_SIZE) {
-            LogPrintf("Leaving block file %i: %s\n", nFile, vinfoBlockFile[nFile].ToString());
-            FlushBlockFile(true);
             nFile++;
             if (vinfoBlockFile.size() <= nFile) {
                 vinfoBlockFile.resize(nFile + 1);
@@ -2528,7 +2551,14 @@ bool FindBlockPos(CValidationState &state, CDiskBlockPos &pos, unsigned int nAdd
         pos.nPos = vinfoBlockFile[nFile].nSize;
     }
 
-    nLastBlockFile = nFile;
+    if (nFile != nLastBlockFile) {
+        if (!fKnown) {
+            LogPrintf("Leaving block file %i: %s\n", nFile, vinfoBlockFile[nFile].ToString());
+        }
+        FlushBlockFile(!fKnown);
+        nLastBlockFile = nFile;
+    }
+
     vinfoBlockFile[nFile].AddBlock(nHeight, nTime);
     if (fKnown)
         vinfoBlockFile[nFile].nSize = std::max(pos.nPos + nAddSize, vinfoBlockFile[nFile].nSize);
@@ -2723,10 +2753,15 @@ bool ContextualCheckBlock(const CBlock& block, CValidationState& state, CBlockIn
     const Consensus::Params& consensusParams = Params().GetConsensus();
 
     // Check that all transactions are finalized
-    BOOST_FOREACH(const CTransaction& tx, block.vtx)
-        if (!IsFinalTx(tx, nHeight, block.GetBlockTime())) {
+    BOOST_FOREACH(const CTransaction& tx, block.vtx) {
+        int nLockTimeFlags = 0;
+        int64_t nLockTimeCutoff = (nLockTimeFlags & LOCKTIME_MEDIAN_TIME_PAST)
+                                ? pindexPrev->GetMedianTimePast()
+                                : block.GetBlockTime();
+        if (!IsFinalTx(tx, nHeight, nLockTimeCutoff)) {
             return state.DoS(10, error("%s: contains a non-final transaction", __func__), REJECT_INVALID, "bad-txns-nonfinal");
         }
+    }
 
     // Enforce block.nVersion=2 rule that the coinbase starts with serialized block height
     // if 750 of the last 1,000 blocks are version 2 or greater (51/100 if testnet):