Merge #839: [0.18 backport] Index the genesis block with txindex

b23efb2 Improve coinbase and issuance tx testing for txindex (Steven Roose)
91ad748 Index the genesis block with txindex (Steven Roose)

Pull request description:

  Backport of #838.

Tree-SHA512: 19597a30d117efd33bf76709c3428def9bfa374f356a5e52a81d617794fb985d3e663ed8911422916d4af113f618d276442fdb0e503cf4df6a1a09e04b63a64a

Author: stevenroose

src/index/txindex.cpp

@@ -246,7 +246,8 @@ bool TxIndex::Init()
 bool TxIndex::WriteBlock(const CBlock& block, const CBlockIndex* pindex)
 {
     // Exclude genesis block transaction because outputs are not spendable.
-    if (pindex->nHeight == 0) return true;
+    //ELEMENTS: we do index the genesis block
+    //if (pindex->nHeight == 0) return true;
 
     CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(block.vtx.size()));
     std::vector<std::pair<uint256, CDiskTxPos>> vPos;

src/test/txindex_tests.cpp

@@ -40,9 +40,10 @@ BOOST_FIXTURE_TEST_CASE(txindex_initial_sync, TestChain100Setup)
     }
 
     // Check that txindex excludes genesis block transactions.
+    //ELEMENTS: we do include them
     const CBlock& genesis_block = Params().GenesisBlock();
     for (const auto& txn : genesis_block.vtx) {
-        BOOST_CHECK(!txindex.FindTx(txn->GetHash(), block_hash, tx_disk));
+        BOOST_CHECK(txindex.FindTx(txn->GetHash(), block_hash, tx_disk));
     }
 
     // Check that txindex has all txs that were in the chain before it started.

test/functional/feature_connect_genesis_outputs.py

@@ -16,7 +16,7 @@ def set_test_params(self):
         self.num_nodes = 2
         self.setup_clean_chain = True
         # First node doesn't connect coinbase output to db, second does
-        self.extra_args = [["-con_connect_genesis_outputs=0", "-initialfreecoins={}".format(NUM_INITIAL_COINS * COIN)],
+        self.extra_args = [["-con_connect_genesis_outputs=0", "-initialfreecoins={}".format(NUM_INITIAL_COINS * COIN), '-txindex=1'],
                            ["-con_connect_genesis_outputs=1", "-initialfreecoins={}".format(NUM_INITIAL_COINS * COIN), '-anyonecanspendaremine=1']]
 
     def skip_test_if_missing_module(self):
@@ -49,15 +49,22 @@ def run_test(self):
         assert_equal(unspent[0]["amount"], NUM_INITIAL_COINS)
         assert_equal(unspent[0]["confirmations"], 1)
 
-        # Test rpc getraw functionality
+        # Test rpc getraw functionality.
 
-        # Coinbase transaction is provably unspendable (OP_RETURN), so even AddCoin won't add it
-        assert_raises_rpc_error(-5, "No such mempool transaction. Use -txindex to enable blockchain transaction queries. Use gettransaction for wallet transactions.", self.nodes[0].getrawtransaction, coinbase_tx)
-        assert_raises_rpc_error(-5, "No such mempool transaction. Use -txindex to enable blockchain transaction queries. Use gettransaction for wallet transactions.", self.nodes[1].getrawtransaction, coinbase_tx)
+        # Node 0 has txindex.
+        self.nodes[0].getrawtransaction(coinbase_tx, False)
+        self.nodes[0].getrawtransaction(issuance_tx, False)
 
-        # Issuance transaction is an OP_TRUE, so will be available to second node
-        assert_raises_rpc_error(-5, "No such mempool transaction. Use -txindex to enable blockchain transaction queries. Use gettransaction for wallet transactions.", self.nodes[0].getrawtransaction, issuance_tx)
+        # Node 1 doesn't.
+        assert_raises_rpc_error(-5, "No such mempool transaction. Use -txindex to enable blockchain transaction queries. Use gettransaction for wallet transactions.", self.nodes[1].getrawtransaction, coinbase_tx)
+        assert_raises_rpc_error(-5, "No such mempool transaction. Use -txindex to enable blockchain transaction queries. Use gettransaction for wallet transactions.", self.nodes[1].getrawtransaction, issuance_tx)
+        # But it can still access them by providing the genesis block hash.
+        self.nodes[1].getrawtransaction(coinbase_tx, False, self.nodes[0].getblockhash(0))
         self.nodes[1].getrawtransaction(issuance_tx, False, self.nodes[0].getblockhash(0))
 
+        # Because the issuance tx is OP_TRUE, node 1 (with anyonecanspendaremine) has them in the wallet.
+        assert_raises_rpc_error(-5, "Invalid or non-wallet transaction id", self.nodes[0].gettransaction, issuance_tx)
+        self.nodes[1].gettransaction(issuance_tx)
+
 if __name__ == '__main__':
     ConnectGenesisTest().main()