Split the part that read the blockundo data from disk so the actual u…

src/Makefile.test.include

@@ -122,6 +122,7 @@ BITCOIN_TESTS =\
   test/txvalidationcache_tests.cpp \
   test/versionbits_tests.cpp \
   test/uint256_tests.cpp \
+  test/undo_tests.cpp \
   test/univalue_tests.cpp \
   test/util_tests.cpp
 

src/test/undo_tests.cpp

@@ -0,0 +1,105 @@
+// Copyright (c) 2017 Amaury SÉCHET
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include "undo.h"
+#include "chainparams.h"
+#include "consensus/validation.h"
+#include "validation.h"
+
+#include "test/test_bitcoin.h"
+
+#include <boost/test/unit_test.hpp>
+
+BOOST_FIXTURE_TEST_SUITE(undo_tests, BasicTestingSetup)
+
+static void UpdateUTXOSet(const CBlock &block, CCoinsViewCache &view,
+                          CBlockUndo &blockundo,
+                          const CChainParams &chainparams, uint32_t nHeight) {
+    CValidationState state;
+
+    auto &coinbaseTx = *block.vtx[0];
+    UpdateCoins(coinbaseTx, view, nHeight);
+
+    for (size_t i = 1; i < block.vtx.size(); i++) {
+        auto &tx = *block.vtx[1];
+
+        blockundo.vtxundo.push_back(CTxUndo());
+        UpdateCoins(tx, view, blockundo.vtxundo.back(), nHeight);
+    }
+
+    view.SetBestBlock(block.GetHash());
+}
+
+static void UndoBlock(const CBlock &block, CCoinsViewCache &view,
+                      const CBlockUndo &blockundo,
+                      const CChainParams &chainparams, uint32_t nHeight) {
+    CValidationState state;
+
+    CBlockIndex pindex;
+    pindex.nHeight = nHeight;
+
+    ApplyBlockUndo(block, state, &pindex, view, blockundo);
+}
+
+static bool HashSpendableCoin(const CCoinsViewCache &view, uint256 txid) {
+    const CCoins *coins = view.AccessCoins(txid);
+    return coins != nullptr && !coins->IsPruned();
+}
+
+BOOST_AUTO_TEST_CASE(connect_utxo_extblock) {
+    SelectParams(CBaseChainParams::MAIN);
+    const CChainParams &chainparams = Params();
+
+    CBlock block;
+    CMutableTransaction tx;
+
+    CCoinsView coinsDummy;
+    CCoinsViewCache view(&coinsDummy);
+
+    block.hashPrevBlock = GetRandHash();
+    view.SetBestBlock(block.hashPrevBlock);
+
+    // Create a block with coinbase and resolution transaction.
+    tx.vin.resize(1);
+    tx.vin[0].scriptSig.resize(10);
+    tx.vout.resize(1);
+    tx.vout[0].nValue = 42;
+    auto coinbaseTx = CTransaction(tx);
+
+    block.vtx.resize(2);
+    block.vtx[0] = MakeTransactionRef(tx);
+
+    tx.vout[0].scriptPubKey = CScript() << OP_TRUE;
+    tx.vin[0].prevout.hash = GetRandHash();
+    tx.vin[0].prevout.n = 0;
+    tx.vin[0].nSequence = CTxIn::SEQUENCE_FINAL;
+    tx.vin[0].scriptSig.resize(0);
+    tx.nVersion = 2;
+
+    auto prevTx0 = CTransaction(tx);
+    view.ModifyNewCoins(prevTx0.GetId(), prevTx0.IsCoinBase())
+        ->FromTx(prevTx0, 100);
+
+    tx.vin[0].prevout.hash = prevTx0.GetId();
+    auto tx0 = CTransaction(tx);
+    block.vtx[1] = MakeTransactionRef(tx0);
+
+    // Now update the UTXO set.
+    CBlockUndo blockundo;
+    UpdateUTXOSet(block, view, blockundo, chainparams, 123456);
+
+    BOOST_CHECK(view.GetBestBlock() == block.GetHash());
+    BOOST_CHECK(HashSpendableCoin(view, coinbaseTx.GetId()));
+    BOOST_CHECK(HashSpendableCoin(view, tx0.GetId()));
+    BOOST_CHECK(!HashSpendableCoin(view, prevTx0.GetId()));
+
+    UndoBlock(block, view, blockundo, chainparams, 123456);
+
+    BOOST_CHECK(view.GetBestBlock() == block.hashPrevBlock);
+    BOOST_CHECK(!HashSpendableCoin(view, coinbaseTx.GetId()));
+    BOOST_CHECK(!HashSpendableCoin(view, tx0.GetId()));
+    BOOST_CHECK(HashSpendableCoin(view, prevTx0.GetId()));
+}
+
+BOOST_AUTO_TEST_SUITE_END()

src/undo.h

@@ -1,5 +1,6 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
+// Copyright (c) 2017 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -10,6 +11,11 @@
 #include "primitives/transaction.h"
 #include "serialize.h"
 
+class CBlock;
+class CBlockIndex;
+class CCoinsViewCache;
+class CValidationState;
+
 /** Undo information for a CTxIn
  *
  *  Contains the prevout's CTxOut being spent, and if this was the
@@ -77,4 +83,14 @@ class CBlockUndo {
     }
 };
 
+/** Apply the undo operation of a CTxInUndo to the given chain state. */
+bool ApplyTxInUndo(const CTxInUndo &undo, CCoinsViewCache &view,
+                   const COutPoint &out);
+
+/** Undo a block from the block and the undoblock data.
+ * See DisconnectBlock for more details. */
+bool ApplyBlockUndo(const CBlock &block, CValidationState &state,
+                    const CBlockIndex *pindex, CCoinsViewCache &coins,
+                    const CBlockUndo &blockUndo, bool *pfClean = nullptr);
+
 #endif // BITCOIN_UNDO_H

src/validation.cpp

@@ -1,5 +1,6 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
+// Copyright (c) 2017 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -1221,7 +1222,7 @@ void UpdateCoins(const CTransaction &tx, CCoinsViewCache &inputs,
     // mark inputs spent
     if (!tx.IsCoinBase()) {
         txundo.vprevout.reserve(tx.vin.size());
-        BOOST_FOREACH (const CTxIn &txin, tx.vin) {
+        for (const CTxIn &txin : tx.vin) {
             CCoinsModifier coins = inputs.ModifyCoins(txin.prevout.hash);
             unsigned nPos = txin.prevout.n;
 
@@ -1506,61 +1507,69 @@ bool DisconnectBlock(const CBlock &block, CValidationState &state,
 
     if (pfClean) *pfClean = false;
 
-    bool fClean = true;
-
     CBlockUndo blockUndo;
     CDiskBlockPos pos = pindex->GetUndoPos();
     if (pos.IsNull()) return error("DisconnectBlock(): no undo data available");
     if (!UndoReadFromDisk(blockUndo, pos, pindex->pprev->GetBlockHash()))
         return error("DisconnectBlock(): failure reading undo data");
 
+    return ApplyBlockUndo(block, state, pindex, view, blockUndo, pfClean);
+}
+
+bool ApplyBlockUndo(const CBlock &block, CValidationState &state,
+                    const CBlockIndex *pindex, CCoinsViewCache &view,
+                    const CBlockUndo &blockUndo, bool *pfClean) {
+    if (pfClean) *pfClean = false;
+    bool fClean = true;
+
     if (blockUndo.vtxundo.size() + 1 != block.vtx.size())
         return error("DisconnectBlock(): block and undo data inconsistent");
 
-    // undo transactions in reverse order
-    for (int i = block.vtx.size() - 1; i >= 0; i--) {
+    // Undo transactions in reverse order.
+    size_t i = block.vtx.size();
+    while (i-- > 0) {
         const CTransaction &tx = *(block.vtx[i]);
         uint256 txid = tx.GetId();
 
         // Check that all outputs are available and match the outputs in the
-        // block itself
-        // exactly.
+        // block itself exactly.
         {
             CCoinsModifier outs = view.ModifyCoins(txid);
             outs->ClearUnspendable();
 
             CCoins outsBlock(tx, pindex->nHeight);
-            // The CCoins serialization does not serialize negative numbers.
-            // No network rules currently depend on the version here, so an
-            // inconsistency is harmless
-            // but it must be corrected before txout nversion ever influences a
-            // network rule.
+            // The CCoins serialization does not serialize negative numbers. No
+            // network rules currently depend on the version here, so an
+            // inconsistency is harmless but it must be corrected before txout
+            // nversion ever influences a network rule.
             if (outsBlock.nVersion < 0) outs->nVersion = outsBlock.nVersion;
             if (*outs != outsBlock)
                 fClean = fClean && error("DisconnectBlock(): added transaction "
                                          "mismatch? database corrupted");
 
-            // remove outputs
+            // Remove outputs.
             outs->Clear();
         }
 
-        // restore inputs
-        if (i > 0) { // not coinbases
-            const CTxUndo &txundo = blockUndo.vtxundo[i - 1];
-            if (txundo.vprevout.size() != tx.vin.size())
-                return error("DisconnectBlock(): transaction and undo data "
-                             "inconsistent");
-            for (unsigned int j = tx.vin.size(); j-- > 0;) {
-                const COutPoint &out = tx.vin[j].prevout;
-                const CTxInUndo &undo = txundo.vprevout[j];
-                if (!ApplyTxInUndo(undo, view, out)) fClean = false;
-            }
+        // Restore inputs.
+        if (i < 1) {
+            // Skip the coinbase.
+            continue;
         }
-    }
 
-    // move best block pointer to prevout block
-    view.SetBestBlock(pindex->pprev->GetBlockHash());
+        const CTxUndo &txundo = blockUndo.vtxundo[i - 1];
+        if (txundo.vprevout.size() != tx.vin.size())
+            return error("DisconnectBlock(): transaction and undo data "
+                         "inconsistent");
+        for (unsigned int j = tx.vin.size(); j-- > 0;) {
+            const COutPoint &out = tx.vin[j].prevout;
+            const CTxInUndo &undo = txundo.vprevout[j];
+            if (!ApplyTxInUndo(undo, view, out)) fClean = false;
+        }
+    }
 
+    // Move best block pointer to previous block.
+    view.SetBestBlock(block.hashPrevBlock);
     if (pfClean) {
         *pfClean = fClean;
         return true;

src/validation.h

@@ -1,5 +1,6 @@
 // Copyright (c) 2009-2010 Satoshi Nakamoto
 // Copyright (c) 2009-2016 The Bitcoin Core developers
+// Copyright (c) 2017 The Bitcoin developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -40,6 +41,7 @@ class CInv;
 class CConnman;
 class CScriptCheck;
 class CTxMemPool;
+class CTxUndo;
 class CValidationInterface;
 class CValidationState;
 struct ChainTxData;
@@ -436,6 +438,8 @@ bool CheckInputs(const CTransaction &tx, CValidationState &state,
 
 /** Apply the effects of this transaction on the UTXO set represented by view */
 void UpdateCoins(const CTransaction &tx, CCoinsViewCache &inputs, int nHeight);
+void UpdateCoins(const CTransaction &tx, CCoinsViewCache &inputs,
+                 CTxUndo &txundo, int nHeight);
 
 /** Transaction validation functions */
 
@@ -590,7 +594,7 @@ bool ConnectBlock(const CBlock &block, CValidationState &state,
  * any case, coins may be modified. */
 bool DisconnectBlock(const CBlock &block, CValidationState &state,
                      const CBlockIndex *pindex, CCoinsViewCache &coins,
-                     bool *pfClean = NULL);
+                     bool *pfClean = nullptr);
 
 /** Check a block is completely valid from start to finish (only works on top of
  * our current best block, with cs_main held) */