Merge ElementsProject#838: Index the genesis block with txindex

fd4dcf9 Improve coinbase and issuance tx testing for txindex (Steven Roose)
ac9966f Index the genesis block with txindex (Steven Roose)

Pull request description:

  This reverts commit ed12d5d in which Core removed the genesis txs from the txindex.

  Since they are spendable in Elements (as opposed to Core), they should be added to the index as well.

Tree-SHA512: a9067032f80a78f5393437d287022756816a4baa6bfb8fc382d04dc7831a536dc68959a039636aa4b1bb268b2b849e67a0d4ca59abe835c2834ac358f8175e9e

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()