Merge pull request #6915

2d8860e Fix removeForReorg to use MedianTimePast (Suhas Daftuar)
b7fa4aa Don't call removeForReorg if DisconnectTip fails (Suhas Daftuar)
7e49f5f Track coinbase spends in CTxMemPoolEntry (Suhas Daftuar)
bb8ea1f removeForReorg calls once-per-disconnect-> once-per-reorg (Matt Corallo)
474b84a Make indentation in ActivateBestChainStep readable (Matt Corallo)
b0a064c Fix comment in removeForReorg (Matt Corallo)
9b060e5 Fix removal of time-locked transactions during reorg (Matt Corallo)
0c9959a Add failing test checking timelocked-txn removal during reorg (Matt Corallo)

1 files changed, 52 insertions, 41 deletions

diff --git a/src/main.cpp b/src/main.cpp
index eea53a58de..162cd03b30 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -953,7 +953,18 @@ bool AcceptToMemoryPool(CTxMemPool& pool, CValidationState &state, const CTransa
         CAmount inChainInputValue;
         double dPriority = view.GetPriority(tx, chainActive.Height(), inChainInputValue);
 
-        CTxMemPoolEntry entry(tx, nFees, GetTime(), dPriority, chainActive.Height(), pool.HasNoInputsOf(tx), inChainInputValue);
+        // Keep track of transactions that spend a coinbase, which we re-scan
+        // during reorgs to ensure COINBASE_MATURITY is still met.
+        bool fSpendsCoinbase = false;
+        BOOST_FOREACH(const CTxIn &txin, tx.vin) {
+            const CCoins *coins = view.AccessCoins(txin.prevout.hash);
+            if (coins->IsCoinBase()) {
+                fSpendsCoinbase = true;
+                break;
+            }
+        }
+
+        CTxMemPoolEntry entry(tx, nFees, GetTime(), dPriority, chainActive.Height(), pool.HasNoInputsOf(tx), inChainInputValue, fSpendsCoinbase);
         unsigned int nSize = entry.GetTxSize();
 
         // Don't accept it if it can't get into a block
@@ -2310,12 +2321,11 @@ void static UpdateTip(CBlockIndex *pindexNew) {
     }
 }
 
-/** Disconnect chainActive's tip. You want to manually re-limit mempool size after this */
+/** Disconnect chainActive's tip. You probably want to call mempool.removeForReorg and manually re-limit mempool size after this, with cs_main held. */
 bool static DisconnectTip(CValidationState& state, const Consensus::Params& consensusParams)
 {
     CBlockIndex *pindexDelete = chainActive.Tip();
     assert(pindexDelete);
-    mempool.check(pcoinsTip);
     // Read block from disk.
     CBlock block;
     if (!ReadBlockFromDisk(block, pindexDelete, consensusParams))
@@ -2350,8 +2360,6 @@ bool static DisconnectTip(CValidationState& state, const Consensus::Params& cons
     // UpdateTransactionsFromBlock finds descendants of any transactions in this
     // block that were added back and cleans up the mempool state.
     mempool.UpdateTransactionsFromBlock(vHashUpdate);
-    mempool.removeCoinbaseSpends(pcoinsTip, pindexDelete->nHeight);
-    mempool.check(pcoinsTip);
     // Update chainActive and related variables.
     UpdateTip(pindexDelete->pprev);
     // Let wallets know transactions went from 1-confirmed to
@@ -2375,7 +2383,6 @@ static int64_t nTimePostConnect = 0;
 bool static ConnectTip(CValidationState& state, const CChainParams& chainparams, CBlockIndex* pindexNew, const CBlock* pblock)
 {
     assert(pindexNew->pprev == chainActive.Tip());
-    mempool.check(pcoinsTip);
     // Read block from disk.
     int64_t nTime1 = GetTimeMicros();
     CBlock block;
@@ -2412,7 +2419,6 @@ bool static ConnectTip(CValidationState& state, const CChainParams& chainparams,
     // Remove conflicting transactions from the mempool.
     list<CTransaction> txConflicted;
     mempool.removeForBlock(pblock->vtx, pindexNew->nHeight, txConflicted, !IsInitialBlockDownload());
-    mempool.check(pcoinsTip);
     // Update chainActive & related variables.
     UpdateTip(pindexNew);
     // Tell wallet about transactions that went from mempool
@@ -2525,46 +2531,49 @@ static bool ActivateBestChainStep(CValidationState& state, const CChainParams& c
     bool fContinue = true;
     int nHeight = pindexFork ? pindexFork->nHeight : -1;
     while (fContinue && nHeight != pindexMostWork->nHeight) {
-    // Don't iterate the entire list of potential improvements toward the best tip, as we likely only need
-    // a few blocks along the way.
-    int nTargetHeight = std::min(nHeight + 32, pindexMostWork->nHeight);
-    vpindexToConnect.clear();
-    vpindexToConnect.reserve(nTargetHeight - nHeight);
-    CBlockIndex *pindexIter = pindexMostWork->GetAncestor(nTargetHeight);
-    while (pindexIter && pindexIter->nHeight != nHeight) {
-        vpindexToConnect.push_back(pindexIter);
-        pindexIter = pindexIter->pprev;
-    }
-    nHeight = nTargetHeight;
-
-    // Connect new blocks.
-    BOOST_REVERSE_FOREACH(CBlockIndex *pindexConnect, vpindexToConnect) {
-        if (!ConnectTip(state, chainparams, pindexConnect, pindexConnect == pindexMostWork ? pblock : NULL)) {
-            if (state.IsInvalid()) {
-                // The block violates a consensus rule.
-                if (!state.CorruptionPossible())
-                    InvalidChainFound(vpindexToConnect.back());
-                state = CValidationState();
-                fInvalidFound = true;
-                fContinue = false;
-                break;
+        // Don't iterate the entire list of potential improvements toward the best tip, as we likely only need
+        // a few blocks along the way.
+        int nTargetHeight = std::min(nHeight + 32, pindexMostWork->nHeight);
+        vpindexToConnect.clear();
+        vpindexToConnect.reserve(nTargetHeight - nHeight);
+        CBlockIndex *pindexIter = pindexMostWork->GetAncestor(nTargetHeight);
+        while (pindexIter && pindexIter->nHeight != nHeight) {
+            vpindexToConnect.push_back(pindexIter);
+            pindexIter = pindexIter->pprev;
+        }
+        nHeight = nTargetHeight;
+
+        // Connect new blocks.
+        BOOST_REVERSE_FOREACH(CBlockIndex *pindexConnect, vpindexToConnect) {
+            if (!ConnectTip(state, chainparams, pindexConnect, pindexConnect == pindexMostWork ? pblock : NULL)) {
+                if (state.IsInvalid()) {
+                    // The block violates a consensus rule.
+                    if (!state.CorruptionPossible())
+                        InvalidChainFound(vpindexToConnect.back());
+                    state = CValidationState();
+                    fInvalidFound = true;
+                    fContinue = false;
+                    break;
+                } else {
+                    // A system error occurred (disk space, database error, ...).
+                    return false;
+                }
             } else {
-                // A system error occurred (disk space, database error, ...).
-                return false;
-            }
-        } else {
-            PruneBlockIndexCandidates();
-            if (!pindexOldTip || chainActive.Tip()->nChainWork > pindexOldTip->nChainWork) {
-                // We're in a better position than we were. Return temporarily to release the lock.
-                fContinue = false;
-                break;
+                PruneBlockIndexCandidates();
+                if (!pindexOldTip || chainActive.Tip()->nChainWork > pindexOldTip->nChainWork) {
+                    // We're in a better position than we were. Return temporarily to release the lock.
+                    fContinue = false;
+                    break;
+                }
             }
         }
     }
-    }
 
-    if (fBlocksDisconnected)
+    if (fBlocksDisconnected) {
+        mempool.removeForReorg(pcoinsTip, chainActive.Tip()->nHeight + 1, STANDARD_LOCKTIME_VERIFY_FLAGS);
         mempool.TrimToSize(GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000);
+    }
+    mempool.check(pcoinsTip);
 
     // Callbacks/notifications for a new best chain.
     if (fInvalidFound)
@@ -2672,6 +2681,7 @@ bool InvalidateBlock(CValidationState& state, const Consensus::Params& consensus
         // ActivateBestChain considers blocks already in chainActive
         // unconditionally valid already, so force disconnect away from it.
         if (!DisconnectTip(state, consensusParams)) {
+            mempool.removeForReorg(pcoinsTip, chainActive.Tip()->nHeight + 1, STANDARD_LOCKTIME_VERIFY_FLAGS);
             return false;
         }
     }
@@ -2689,6 +2699,7 @@ bool InvalidateBlock(CValidationState& state, const Consensus::Params& consensus
     }
 
     InvalidChainFound(pindex);
+    mempool.removeForReorg(pcoinsTip, chainActive.Tip()->nHeight + 1, STANDARD_LOCKTIME_VERIFY_FLAGS);
     return true;
 }