Fix assumeutxo crash due to invalid base_blockhash

Can be reviewed with --color-moved=dimmed-zebra --color-moved-ws=ignore-all-space

src/test/validation_chainstatemanager_tests.cpp

@@ -260,6 +260,11 @@ BOOST_FIXTURE_TEST_CASE(chainstatemanager_activate_snapshot, TestChain100Setup)
  // Coins count is smaller than coins in file
  metadata.m_coins_count -= 1;
  }));
+ BOOST_REQUIRE(!CreateAndActivateUTXOSnapshot(
+ m_node, m_path_root, [](CAutoFile& auto_infile, SnapshotMetadata& metadata) {
+ // Wrong hash
+ metadata.m_base_blockhash = uint256::ZERO;
+ }));
  BOOST_REQUIRE(!CreateAndActivateUTXOSnapshot(
  m_node, m_path_root, [](CAutoFile& auto_infile, SnapshotMetadata& metadata) {
  // Wrong hash

src/validation.cpp

@@ -4815,6 +4815,26 @@ bool ChainstateManager::PopulateAndValidateSnapshot(
 
  uint256 base_blockhash = metadata.m_base_blockhash;
 
+ CBlockIndex* snapshot_start_block = WITH_LOCK(::cs_main, return m_blockman.LookupBlockIndex(base_blockhash));
+
+ if (!snapshot_start_block) {
+ // Needed for GetUTXOStats and ExpectedAssumeutxo to determine the height and to avoid a crash when base_blockhash.IsNull()
+ LogPrintf("[snapshot] Did not find snapshot start blockheader %s\n",
+ base_blockhash.ToString());
+ return false;
+ }
+
+ int base_height = snapshot_start_block->nHeight;
+ auto maybe_au_data = ExpectedAssumeutxo(base_height, ::Params());
+
+ if (!maybe_au_data) {
+ LogPrintf("[snapshot] assumeutxo height in snapshot metadata not recognized " /* Continued */
+ "(%d) - refusing to load snapshot\n", base_height);
+ return false;
+ }
+
+ const AssumeutxoData& au_data = *maybe_au_data;
+
  COutPoint outpoint;
  Coin coin;
  const uint64_t coins_count = metadata.m_coins_count;
@@ -4905,15 +4925,6 @@ bool ChainstateManager::PopulateAndValidateSnapshot(
 
  assert(coins_cache.GetBestBlock() == base_blockhash);
 
- CBlockIndex* snapshot_start_block = WITH_LOCK(::cs_main, return m_blockman.LookupBlockIndex(base_blockhash));
-
- if (!snapshot_start_block) {
- // Needed for GetUTXOStats to determine the height
- LogPrintf("[snapshot] Did not find snapshot start blockheader %s\n",
- base_blockhash.ToString());
- return false;
- }
-
  CCoinsStats stats{CoinStatsHashType::HASH_SERIALIZED};
  auto breakpoint_fnc = [] { /* TODO insert breakpoint here? */ };
 
@@ -4927,18 +4938,6 @@ bool ChainstateManager::PopulateAndValidateSnapshot(
  }
 
  // Assert that the deserialized chainstate contents match the expected assumeutxo value.
-
- int base_height = snapshot_start_block->nHeight;
- auto maybe_au_data = ExpectedAssumeutxo(base_height, ::Params());
-
- if (!maybe_au_data) {
- LogPrintf("[snapshot] assumeutxo height in snapshot metadata not recognized " /* Continued */
- "(%d) - refusing to load snapshot\n", base_height);
- return false;
- }
-
- const AssumeutxoData& au_data = *maybe_au_data;
-
  if (AssumeutxoHash{stats.hashSerialized} != au_data.hash_serialized) {
  LogPrintf("[snapshot] bad snapshot content hash: expected %s, got %s\n",
  au_data.hash_serialized.ToString(), stats.hashSerialized.ToString());