text: // Copyright (c) 2012-2014 The Bitcoin Core developers
  // Copyright (c) 2019-2020 The KSOC developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "wallet/wallet.h"
  #include "consensus/merkle.h"
  
  #include <set>
  #include <stdint.h>
  #include <utility>
  #include <vector>
  
  #include <boost/test/unit_test.hpp>
  #include "wallet/test/wallet_test_fixture.h"
  
  // how many times to run all the tests to have a chance to catch errors that only show up with particular random shuffles
  #define RUN_TESTS 100
  
  // some tests fail 1% of the time due to bad luck.
  // we repeat those tests this many times and only complain if all iterations of the test fail
  #define RANDOM_REPEATS 5
  
  
  typedef std::set<std::pair<const CWalletTx*,unsigned int> > CoinSet;
  
  BOOST_FIXTURE_TEST_SUITE(wallet_tests, WalletTestingSetup)
  
  static std::vector<COutput> vCoins;
  
  static void add_coin(const CAmount& nValue, int nAge = 6*24, bool fIsFromMe = false, int nInput=0)
  {
      static int nextLockTime = 0;
      CMutableTransaction tx;
      tx.nLockTime = nextLockTime++;        // so all transactions get different hashes
      tx.vout.resize(nInput+1);
      tx.vout[nInput].nValue = nValue;
      if (fIsFromMe) {
          // IsFromMe() returns (GetDebit() > 0), and GetDebit() is 0 if vin.empty(),
          // so stop vin being empty, and cache a non-zero Debit to fake out IsFromMe()
          tx.vin.resize(1);
      }
      CWalletTx* wtx = new CWalletTx(pwalletMain, tx);
      if (fIsFromMe) {
          wtx->m_amounts[CWalletTx::DEBIT].Set(ISMINE_SPENDABLE, 1);
      }
      COutput output(wtx, nInput, nAge, true, true);
      vCoins.push_back(output);
  }
  
  static void empty_wallet(void)
  {
      for (COutput output : vCoins)
          delete output.tx;
      vCoins.clear();
  }
  
  static bool equal_sets(CoinSet a, CoinSet b)
  {
      std::pair<CoinSet::iterator, CoinSet::iterator> ret = mismatch(a.begin(), a.end(), b.begin());
      return ret.first == a.end() && ret.second == b.end();
  }
  
  BOOST_AUTO_TEST_CASE(coin_selection_tests)
  {
      CoinSet setCoinsRet, setCoinsRet2;
      CAmount nValueRet;
  
      LOCK(pwalletMain->cs_wallet);
  
      // test multiple times to allow for differences in the shuffle order
      for (int i = 0; i < RUN_TESTS; i++)
      {
          empty_wallet();
  
          // with an empty wallet we can't even pay one cent
          BOOST_CHECK(!pwalletMain->SelectCoinsMinConf( 1 * CENT, 1, 6, vCoins, setCoinsRet, nValueRet));
  
          add_coin(1*CENT, 4);        // add a new 1 cent coin
  
          // with a new 1 cent coin, we still can't find a mature 1 cent
          BOOST_CHECK(!pwalletMain->SelectCoinsMinConf( 1 * CENT, 1, 6, vCoins, setCoinsRet, nValueRet));
  
          // but we can find a new 1 cent
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf( 1 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 1 * CENT);
  
          add_coin(2*CENT);           // add a mature 2 cent coin
  
          // we can't make 3 cents of mature coins
          BOOST_CHECK(!pwalletMain->SelectCoinsMinConf( 3 * CENT, 1, 6, vCoins, setCoinsRet, nValueRet));
  
          // we can make 3 cents of new  coins
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf( 3 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 3 * CENT);
  
          add_coin(5*CENT);           // add a mature 5 cent coin,
          add_coin(10*CENT, 3, true); // a new 10 cent coin sent from one of our own addresses
          add_coin(20*CENT);          // and a mature 20 cent coin
  
          // now we have new: 1+10=11 (of which 10 was self-sent), and mature: 2+5+20=27.  total = 38
  
          // we can't make 38 cents only if we disallow new coins:
          BOOST_CHECK(!pwalletMain->SelectCoinsMinConf(38 * CENT, 1, 6, vCoins, setCoinsRet, nValueRet));
          // we can't even make 37 cents if we don't allow new coins even if they're from us
          BOOST_CHECK(!pwalletMain->SelectCoinsMinConf(38 * CENT, 6, 6, vCoins, setCoinsRet, nValueRet));
          // but we can make 37 cents if we accept new coins from ourself
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(37 * CENT, 1, 6, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 37 * CENT);
          // and we can make 38 cents if we accept all new coins
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(38 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 38 * CENT);
  
          // try making 34 cents from 1,2,5,10,20 - we can't do it exactly
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(34 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_GT(nValueRet, 34 * CENT);         // but should get more than 34 cents
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);     // the best should be 20+10+5.  it's incredibly unlikely the 1 or 2 got included (but possible)
  
          // when we try making 7 cents, the smaller coins (1,2,5) are enough.  We should see just 2+5
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf( 7 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 7 * CENT);
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
  
          // when we try making 8 cents, the smaller coins (1,2,5) are exactly enough.
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf( 8 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK(nValueRet == 8 * CENT);
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);
  
          // when we try making 9 cents, no subset of smaller coins is enough, and we get the next bigger coin (10)
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf( 9 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 10 * CENT);
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
  
          // now clear out the wallet and start again to test choosing between subsets of smaller coins and the next biggest coin
          empty_wallet();
  
          add_coin( 6*CENT);
          add_coin( 7*CENT);
          add_coin( 8*CENT);
          add_coin(20*CENT);
          add_coin(30*CENT); // now we have 6+7+8+20+30 = 71 cents total
  
          // check that we have 71 and not 72
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(71 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK(!pwalletMain->SelectCoinsMinConf(72 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
  
          // now try making 16 cents.  the best smaller coins can do is 6+7+8 = 21; not as good at the next biggest coin, 20
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(16 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 20 * CENT); // we should get 20 in one coin
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
  
          add_coin( 5*CENT); // now we have 5+6+7+8+20+30 = 75 cents total
  
          // now if we try making 16 cents again, the smaller coins can make 5+6+7 = 18 cents, better than the next biggest coin, 20
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(16 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 18 * CENT); // we should get 18 in 3 coins
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);
  
          add_coin( 18*CENT); // now we have 5+6+7+8+18+20+30
  
          // and now if we try making 16 cents again, the smaller coins can make 5+6+7 = 18 cents, the same as the next biggest coin, 18
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(16 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 18 * CENT);  // we should get 18 in 1 coin
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U); // because in the event of a tie, the biggest coin wins
  
          // now try making 11 cents.  we should get 5+6
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(11 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 11 * CENT);
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
  
          // check that the smallest bigger coin is used
          add_coin( 1*COIN);
          add_coin( 2*COIN);
          add_coin( 3*COIN);
          add_coin( 4*COIN); // now we have 5+6+7+8+18+20+30+100+200+300+400 = 1094 cents
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(95 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 1 * COIN);  // we should get 1 BTC in 1 coin
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
  
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(195 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 2 * COIN);  // we should get 2 BTC in 1 coin
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
  
          // empty the wallet and start again, now with fractions of a cent, to test sub-cent change avoidance
          empty_wallet();
          add_coin(0.1*CENT);
          add_coin(0.2*CENT);
          add_coin(0.3*CENT);
          add_coin(0.4*CENT);
          add_coin(0.5*CENT);
  
          // try making 1 cent from 0.1 + 0.2 + 0.3 + 0.4 + 0.5 = 1.5 cents
          // we'll get sub-cent change whatever happens, so can expect 1.0 exactly
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(1 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 1 * CENT);
  
          // but if we add a bigger coin, making it possible to avoid sub-cent change, things change:
          add_coin(1111*CENT);
  
          // try making 1 cent from 0.1 + 0.2 + 0.3 + 0.4 + 0.5 + 1111 = 1112.5 cents
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(1 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 1 * CENT); // we should get the exact amount
  
          // if we add more sub-cent coins:
          add_coin(0.6*CENT);
          add_coin(0.7*CENT);
  
          // and try again to make 1.0 cents, we can still make 1.0 cents
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(1 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 1 * CENT); // we should get the exact amount
  
          // run the 'mtgox' test (see http://blockexplorer.com/tx/29a3efd3ef04f9153d47a990bd7b048a4b2d213daaa5fb8ed670fb85f13bdbcf)
          // they tried to consolidate 10 50k coins into one 500k coin, and ended up with 50k in change
          empty_wallet();
          for (int i = 0; i < 20; i++)
              add_coin(50000 * COIN);
  
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(500000 * COIN, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 500000 * COIN); // we should get the exact amount
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 10U); // in ten coins
  
          // if there's not enough in the smaller coins to make at least 1 cent change (0.5+0.6+0.7 < 1.0+1.0),
          // we need to try finding an exact subset anyway
  
          // sometimes it will fail, and so we use the next biggest coin:
          empty_wallet();
          add_coin(0.5 * CENT);
          add_coin(0.6 * CENT);
          add_coin(0.7 * CENT);
          add_coin(1111 * CENT);
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(1 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 1111 * CENT); // we get the bigger coin
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 1U);
  
          // but sometimes it's possible, and we use an exact subset (0.4 + 0.6 = 1.0)
          empty_wallet();
          add_coin(0.4 * CENT);
          add_coin(0.6 * CENT);
          add_coin(0.8 * CENT);
          add_coin(1111 * CENT);
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(1 * CENT, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 1 * CENT);   // we should get the exact amount
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U); // in two coins 0.4+0.6
  
          // test avoiding sub-cent change
          empty_wallet();
          add_coin(0.0005 * COIN);
          add_coin(0.01 * COIN);
          add_coin(1 * COIN);
  
          // trying to make 1.0001 from these three coins
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(1.0001 * COIN, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 1.0105 * COIN);   // we should get all coins
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 3U);
  
          // but if we try to make 0.999, we should take the bigger of the two small coins to avoid sub-cent change
          BOOST_CHECK(pwalletMain->SelectCoinsMinConf(0.999 * COIN, 1, 1, vCoins, setCoinsRet, nValueRet));
          BOOST_CHECK_EQUAL(nValueRet, 1.01 * COIN);   // we should get 1 + 0.01
          BOOST_CHECK_EQUAL(setCoinsRet.size(), 2U);
  
          // test randomness
          {
              empty_wallet();
              for (int i2 = 0; i2 < 100; i2++)
                  add_coin(COIN);
  
              // picking 50 from 100 coins doesn't depend on the shuffle,
              // but does depend on randomness in the stochastic approximation code
              BOOST_CHECK(pwalletMain->SelectCoinsMinConf(50 * COIN, 1, 6, vCoins, setCoinsRet , nValueRet));
              BOOST_CHECK(pwalletMain->SelectCoinsMinConf(50 * COIN, 1, 6, vCoins, setCoinsRet2, nValueRet));
              BOOST_CHECK(!equal_sets(setCoinsRet, setCoinsRet2));
  
              int fails = 0;
              for (int i = 0; i < RANDOM_REPEATS; i++)
              {
                  // selecting 1 from 100 identical coins depends on the shuffle; this test will fail 1% of the time
                  // run the test RANDOM_REPEATS times and only complain if all of them fail
                  BOOST_CHECK(pwalletMain->SelectCoinsMinConf(COIN, 1, 6, vCoins, setCoinsRet , nValueRet));
                  BOOST_CHECK(pwalletMain->SelectCoinsMinConf(COIN, 1, 6, vCoins, setCoinsRet2, nValueRet));
                  if (equal_sets(setCoinsRet, setCoinsRet2))
                      fails++;
              }
              BOOST_CHECK_NE(fails, RANDOM_REPEATS);
  
              // add 75 cents in small change.  not enough to make 90 cents,
              // then try making 90 cents.  there are multiple competing "smallest bigger" coins,
              // one of which should be picked at random
              add_coin( 5*CENT); add_coin(10*CENT); add_coin(15*CENT); add_coin(20*CENT); add_coin(25*CENT);
  
              fails = 0;
              for (int i = 0; i < RANDOM_REPEATS; i++)
              {
                  // selecting 1 from 100 identical coins depends on the shuffle; this test will fail 1% of the time
                  // run the test RANDOM_REPEATS times and only complain if all of them fail
                  BOOST_CHECK(pwalletMain->SelectCoinsMinConf(90*CENT, 1, 6, vCoins, setCoinsRet , nValueRet));
                  BOOST_CHECK(pwalletMain->SelectCoinsMinConf(90*CENT, 1, 6, vCoins, setCoinsRet2, nValueRet));
                  if (equal_sets(setCoinsRet, setCoinsRet2))
                      fails++;
              }
              BOOST_CHECK_NE(fails, RANDOM_REPEATS);
          }
      }
      empty_wallet();
  }
  
  void removeTxFromMempool(CWalletTx& wtx)
  {
      LOCK(mempool.cs);
      if (mempool.exists(wtx.GetHash())) {
          auto it = mempool.mapTx.find(wtx.GetHash());
          if (it != mempool.mapTx.end()) {
              mempool.mapTx.erase(it);
          }
      }
  }
  
  /**
   * Mimic block creation.
   */
  CBlockIndex* SimpleFakeMine(CWalletTx& wtx, CBlockIndex* pprev = nullptr)
  {
      CBlock block;
      block.vtx.push_back(wtx);
      block.hashMerkleRoot = BlockMerkleRoot(block);
      if (pprev) block.hashPrevBlock = pprev->GetBlockHash();
      CBlockIndex* fakeIndex = new CBlockIndex(block);
      fakeIndex->pprev = pprev;
      mapBlockIndex.insert(std::make_pair(block.GetHash(), fakeIndex));
      fakeIndex->phashBlock = &mapBlockIndex.find(block.GetHash())->first;
      chainActive.SetTip(fakeIndex);
      BOOST_CHECK(chainActive.Contains(fakeIndex));
      wtx.SetMerkleBranch(fakeIndex, 0);
      removeTxFromMempool(wtx);
      return fakeIndex;
  }
  
  void fakeMempoolInsertion(const CWalletTx& wtxCredit)
  {
      CTxMemPoolEntry entry(wtxCredit, 0, 0, 0, 0, false, 0, false, 0);
      LOCK(mempool.cs);
      mempool.mapTx.insert(entry);
  }
  
  CWalletTx& BuildAndLoadTxToWallet(const std::vector<CTxIn>& vin,
                                    const std::vector<CTxOut>& vout,
                                    CWallet& wallet)
  {
      CMutableTransaction mTx;
      mTx.vin = vin;
      mTx.vout = vout;
      CTransaction tx(mTx);
      wallet.LoadToWallet({&wallet, tx});
      return wallet.mapWallet[tx.GetHash()];
  }
  
  CWalletTx& ReceiveBalanceWith(const std::vector<CTxOut>& vout,
                            CWallet& wallet)
  {
      std::vector<CTxIn> vin;
      vin.emplace_back(CTxIn(COutPoint(uint256(), 999)));
      return BuildAndLoadTxToWallet(vin, vout, wallet);
  }
  
  void CheckBalances(const CWalletTx& tx,
                     const CAmount& nCreditAll,
                     const CAmount& nCreditSpendable,
                     const CAmount& nAvailableCredit,
                     const CAmount& nDebitAll,
                     const CAmount& nDebitSpendable)
  {
      BOOST_CHECK_EQUAL(tx.GetCredit(ISMINE_ALL), nCreditAll);
      BOOST_CHECK_EQUAL(tx.GetCredit(ISMINE_SPENDABLE), nCreditSpendable);
      BOOST_CHECK(tx.IsAmountCached(CWalletTx::CREDIT, ISMINE_SPENDABLE));
      BOOST_CHECK_EQUAL(tx.GetAvailableCredit(), nAvailableCredit);
      BOOST_CHECK(tx.IsAmountCached(CWalletTx::AVAILABLE_CREDIT, ISMINE_SPENDABLE));
      BOOST_CHECK_EQUAL(tx.GetDebit(ISMINE_ALL), nDebitAll);
      BOOST_CHECK_EQUAL(tx.GetDebit(ISMINE_SPENDABLE), nDebitSpendable);
      BOOST_CHECK(tx.IsAmountCached(CWalletTx::DEBIT, ISMINE_SPENDABLE));
  }
  
  /**
   * Validates the correct behaviour of the CWalletTx "standard" balance methods.
   * (where "standard" is defined by direct P2PKH scripts, no P2CS contracts nor other types)
   *
   * 1) CWalletTx::GetCredit.
   * 2) CWalletTx::GetDebit.
   * 4) CWalletTx::GetAvailableCredit
   * 3) CWallet::GetUnconfirmedBalance.
   */
  BOOST_AUTO_TEST_CASE(cached_balances_tests)
  {
      // 1) Receive balance from an external source and verify:
      // * GetCredit(ISMINE_ALL) correctness (must be equal to 'nCredit' amount)
      // * GetCredit(ISMINE_SPENDABLE) correctness (must be equal to ISMINE_ALL) + must be cached.
      // * GetAvailableCredit() correctness (must be equal to ISMINE_ALL)
      // * GetDebit(ISMINE_ALL) correctness (must be 0)
      // * wallet.GetUnconfirmedBalance() correctness (must be equal 'nCredit')
  
      // 2) Confirm the tx and verify:
      // * wallet.GetUnconfirmedBalance() correctness (must be 0)
      // * GetAvailableCredit() correctness (must be equal to (1) ISMINE_ALL)
  
      // 3) Spend one of the two outputs of the receiving tx to an external source
      // and verify:
      // * creditTx.GetAvailableCredit() correctness (must be equal to 'nCredit' / 2) + must be cached.
      // * debitTx.GetDebit(ISMINE_ALL) correctness (must be equal to 'nCredit' / 2)
      // * debitTx.GetDebit(ISMINE_SPENDABLE) correctness (must be equal to 'nCredit' / 2) + must be cached.
      // * debitTx.GetAvailableCredit() correctness (must be 0).
  
      CAmount nCredit = 20 * COIN;
  
      // Setup wallet
      CWallet &wallet = *pwalletMain;
      LOCK2(cs_main, wallet.cs_wallet);
      wallet.SetMinVersion(FEATURE_PRE_SPLIT_KEYPOOL);
      wallet.SetupSPKM(false);
  
      // Receive balance from an external source
      CTxDestination receivingAddr;
      BOOST_ASSERT(wallet.getNewAddress(receivingAddr, "receiving_address").result);
      CTxOut creditOut(nCredit/2, GetScriptForDestination(receivingAddr));
      CWalletTx& wtxCredit = ReceiveBalanceWith({creditOut, creditOut},wallet);
  
      // Validates (1)
      CheckBalances(
              wtxCredit,
              nCredit,            // CREDIT-ISMINE_ALL
              nCredit,            // CREDIT-ISMINE_SPENDABLE
              nCredit,            // AVAILABLE_CREDIT
              0,                  // DEBIT-ISMINE_ALL
              0                   // DEBIT-ISMINE_SPENDABLE
      );
  
      // GetUnconfirmedBalance requires tx in mempool.
      fakeMempoolInsertion(wtxCredit);
      BOOST_CHECK_EQUAL(wallet.GetUnconfirmedBalance(), nCredit);
  
      // 2) Confirm tx and verify
      SimpleFakeMine(wtxCredit);
      BOOST_CHECK_EQUAL(wallet.GetUnconfirmedBalance(), 0);
      BOOST_CHECK_EQUAL(wtxCredit.GetAvailableCredit(), nCredit);
  
      // 3) Spend one of the two outputs of the receiving tx to an external source and verify.
      // Create debit transaction.
      CAmount nDebit = nCredit / 2;
      std::vector<CTxIn> vinDebit = {CTxIn(COutPoint(wtxCredit.GetHash(), 0))};
      CKey key;
      key.MakeNewKey(true);
      std::vector<CTxOut> voutDebit = {CTxOut(nDebit, GetScriptForDestination(key.GetPubKey().GetID()))};
      CWalletTx& wtxDebit = BuildAndLoadTxToWallet(vinDebit, voutDebit, wallet);
  
      // Validates (3)
  
      // First the debit tx
      CheckBalances(
              wtxDebit,
              0,                   // CREDIT-ISMINE_ALL
              0,                   // CREDIT-ISMINE_SPENDABLE
              0,                   // AVAILABLE_CREDIT
              nDebit,              // DEBIT-ISMINE_ALL
              nDebit               // DEBIT-ISMINE_SPENDABLE
      );
  
      // Secondly the prev credit tx update
  
      // One output spent, the other one not. Force available credit recalculation.
      // If we don't request it, it will not happen.
      BOOST_CHECK_EQUAL(wtxCredit.GetAvailableCredit(false), nCredit - nDebit);
      BOOST_CHECK(wtxCredit.IsAmountCached(CWalletTx::AVAILABLE_CREDIT, ISMINE_SPENDABLE));
  
  }
  
  BOOST_AUTO_TEST_SUITE_END()
  