Keep track of spent notes, and detect and report conflicts

src/wallet/gtest/test_wallet.cpp

@@ -3,6 +3,7 @@
 
 #include "base58.h"
 #include "chainparams.h"
+#include "main.h"
 #include "random.h"
 #include "wallet/wallet.h"
 #include "zcash/JoinSplit.hpp"
@@ -78,6 +79,55 @@ libzcash::Note GetNote(const libzcash::SpendingKey& sk,
     return note_pt.note(sk.address());
 }
 
+CWalletTx GetValidSpend(const libzcash::SpendingKey& sk,
+                        const libzcash::Note& note, CAmount value) {
+    CMutableTransaction mtx;
+    mtx.vout.resize(2);
+    mtx.vout[0].nValue = value;
+    mtx.vout[1].nValue = 0;
+
+    // Generate an ephemeral keypair.
+    uint256 joinSplitPubKey;
+    unsigned char joinSplitPrivKey[crypto_sign_SECRETKEYBYTES];
+    crypto_sign_keypair(joinSplitPubKey.begin(), joinSplitPrivKey);
+    mtx.joinSplitPubKey = joinSplitPubKey;
+
+    // Fake tree for the unused witness
+    ZCIncrementalMerkleTree tree;
+
+    boost::array<libzcash::JSInput, 2> inputs = {
+        libzcash::JSInput(tree.witness(), note, sk),
+        libzcash::JSInput() // dummy input
+    };
+
+    boost::array<libzcash::JSOutput, 2> outputs = {
+        libzcash::JSOutput(), // dummy output
+        libzcash::JSOutput() // dummy output
+    };
+
+    boost::array<libzcash::Note, 2> output_notes;
+
+    // Prepare JoinSplits
+    uint256 rt;
+    JSDescription jsdesc {*params, mtx.joinSplitPubKey, rt,
+                          inputs, outputs, 0, value, false};
+    mtx.vjoinsplit.push_back(jsdesc);
+
+    // Empty output script.
+    CScript scriptCode;
+    CTransaction signTx(mtx);
+    uint256 dataToBeSigned = SignatureHash(scriptCode, signTx, NOT_AN_INPUT, SIGHASH_ALL);
+
+    // Add the signature
+    assert(crypto_sign_detached(&mtx.joinSplitSig[0], NULL,
+                         dataToBeSigned.begin(), 32,
+                         joinSplitPrivKey
+                        ) == 0);
+    CTransaction tx {mtx};
+    CWalletTx wtx {NULL, tx};
+    return wtx;
+}
+
 TEST(wallet_tests, set_note_addrs_in_cwallettx) {
     auto sk = libzcash::SpendingKey::random();
     auto wtx = GetValidReceive(sk, 10, true);
@@ -125,3 +175,74 @@ TEST(wallet_tests, find_note_in_tx) {
     EXPECT_EQ(1, noteMap.count(jsoutpt));
     EXPECT_EQ(nd, noteMap[jsoutpt]);
 }
+
+TEST(wallet_tests, get_conflicted_notes) {
+    CWallet wallet;
+
+    auto sk = libzcash::SpendingKey::random();
+    wallet.AddSpendingKey(sk);
+
+    auto wtx = GetValidReceive(sk, 10, true);
+    auto note = GetNote(sk, wtx, 0, 1);
+    auto nullifier = note.nullifier(sk);
+
+    auto wtx2 = GetValidSpend(sk, note, 5);
+    auto wtx3 = GetValidSpend(sk, note, 10);
+    auto hash2 = wtx2.GetTxid();
+    auto hash3 = wtx3.GetTxid();
+
+    // No conflicts for no spends
+    EXPECT_EQ(0, wallet.GetConflicts(hash2).size());
+    wallet.AddToWallet(wtx, true, NULL);
+    EXPECT_EQ(0, wallet.GetConflicts(hash2).size());
+
+    // No conflicts for one spend
+    wallet.AddToWallet(wtx2, true, NULL);
+    EXPECT_EQ(0, wallet.GetConflicts(hash2).size());
+
+    // Conflicts for two spends
+    wallet.AddToWallet(wtx3, true, NULL);
+    auto c3 = wallet.GetConflicts(hash2);
+    EXPECT_EQ(2, c3.size());
+    EXPECT_EQ(std::set<uint256>({hash2, hash3}), c3);
+}
+
+TEST(wallet_tests, nullifier_is_spent) {
+    CWallet wallet;
+
+    auto sk = libzcash::SpendingKey::random();
+    wallet.AddSpendingKey(sk);
+
+    auto wtx = GetValidReceive(sk, 10, true);
+    auto note = GetNote(sk, wtx, 0, 1);
+    auto nullifier = note.nullifier(sk);
+
+    EXPECT_FALSE(wallet.IsSpent(nullifier));
+
+    wallet.AddToWallet(wtx, true, NULL);
+    EXPECT_FALSE(wallet.IsSpent(nullifier));
+
+    auto wtx2 = GetValidSpend(sk, note, 5);
+    wallet.AddToWallet(wtx2, true, NULL);
+    EXPECT_FALSE(wallet.IsSpent(nullifier));
+
+    // Fake-mine the transaction
+    EXPECT_EQ(-1, chainActive.Height());
+    CBlock block;
+    block.vtx.push_back(wtx2);
+    block.hashMerkleRoot = block.BuildMerkleTree();
+    auto blockHash = block.GetHash();
+    CBlockIndex fakeIndex {block};
+    mapBlockIndex.insert(std::make_pair(blockHash, &fakeIndex));
+    chainActive.SetTip(&fakeIndex);
+    EXPECT_TRUE(chainActive.Contains(&fakeIndex));
+    EXPECT_EQ(0, chainActive.Height());
+
+    wtx2.SetMerkleBranch(block);
+    wallet.AddToWallet(wtx2, true, NULL);
+    EXPECT_TRUE(wallet.IsSpent(nullifier));
+
+    // Tear down
+    chainActive.SetTip(NULL);
+    mapBlockIndex.erase(blockHash);
+}