Merge #14085: index: Fix for indexers skipping genesis block.

ed12d5df1b index: Fix for indexers skipping genesis block. (Jim Posen)

Pull request description:

  This fixes a bug where indexers would skip processing of the genesis block. Preserves the current behavior of omitting genesis block transaction from the index.

Tree-SHA512: 092fd3d629bf1ef279566217c668cc913a8b8e012d811d0e544231894c49a0c0c179537ac4727c39b9bf407479541745d79c4e118db6f0795a2b848d0fe62cbf

src/index/base.cpp

@@ -60,7 +60,11 @@ bool BaseIndex::Init()
     }
 
     LOCK(cs_main);
-    m_best_block_index = FindForkInGlobalIndex(chainActive, locator);
+    if (locator.IsNull()) {
+        m_best_block_index = nullptr;
+    } else {
+        m_best_block_index = FindForkInGlobalIndex(chainActive, locator);
+    }
     m_synced = m_best_block_index.load() == chainActive.Tip();
     return true;
 }

src/index/txindex.cpp

@@ -245,6 +245,9 @@ 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;
+
     CDiskTxPos pos(pindex->GetBlockPos(), GetSizeOfCompactSize(block.vtx.size()));
     std::vector<std::pair<uint256, CDiskTxPos>> vPos;
     vPos.reserve(block.vtx.size());

src/test/txindex_tests.cpp

@@ -2,6 +2,7 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#include <chainparams.h>
 #include <index/txindex.h>
 #include <script/standard.h>
 #include <test/test_bitcoin.h>
@@ -38,6 +39,12 @@ BOOST_FIXTURE_TEST_CASE(txindex_initial_sync, TestChain100Setup)
         MilliSleep(100);
     }
 
+    // Check that txindex excludes genesis block transactions.
+    const CBlock& genesis_block = Params().GenesisBlock();
+    for (const auto& txn : genesis_block.vtx) {
+        BOOST_CHECK(!txindex.FindTx(txn->GetHash(), block_hash, tx_disk));
+    }
+
     // Check that txindex has all txs that were in the chain before it started.
     for (const auto& txn : m_coinbase_txns) {
         if (!txindex.FindTx(txn->GetHash(), block_hash, tx_disk)) {