Merge c9645b4383 into 85f96b01b7

9d2d9f7ce2 rpc: Include assumeutxo as a failure reason of rescanblockchain (Fabian Jahr)
595edee169 test, assumeutxo: import descriptors during background sync (Alfonso Roman Zubeldia)
d73ae603d4 rpc: Improve importdescriptor RPC error messages (Fabian Jahr)
27f99b6d63 validation: Don't assume m_chain_tx_count in GuessVerificationProgress (Fabian Jahr)
42d5d53363 interfaces: Add helper function for wallet on pruning (Fabian Jahr)

Pull request description:

  A test that is added as part of #30455 uncovered this issue: The `GuessVerificationProgress` function is used during during descriptor import and relies on `m_chain_tx_count`. In #29370 an [`Assume` was added](0fd915ee6b) expecting the `m_chaint_tx_count` to be set. However, as the test uncovered, `GuessVerificationProgress` is called with background sync blocks that have `m_chaint_tx_count = 0` when they have not been downloaded and processed yet.

  The simple fix is to remove the `Assume`. Users should not be thrown off by the `Internal bug detected` error. The behavior of `importdescriptor` is kept consistent with the behavior for blocks missing due to pruning.

  The test by alfonsoromanz is cherry-picked here to show that the [CI errors](https://cirrus-ci.com/task/5110045812195328?logs=ci#L2535) should be fixed by this change.

  This PR also improves error messages returned by the `importdescriptors` and `rescanblockchain` RPCs. The error message now changes depending on the situation of the node, i.e. if pruning is happening or an assumutxo backgroundsync is active.

ACKs for top commit:
  achow101:
    ACK 9d2d9f7ce2
  mzumsande:
    Code Review ACK 9d2d9f7ce2
  furszy:
    Code review ACK 9d2d9f7ce2

Tree-SHA512: b841a9b371e5eb8eb3bfebca35645ff2fdded7a3e5e06308d46a33a51ca42cc4c258028c9958fbbb6cda9bb990e07ab8d8504dd9ec6705ef78afe0435912b365

doc/release-notes-31600.md

@@ -0,0 +1,11 @@
+Updated RPCs
+---
+- the `getblocktemplate` RPC `curtime` (BIP22) and `mintime` (BIP23) fields now
+  account for the timewarp fix proposed in BIP94 on all networks. This ensures
+  that, in the event a timewarp fix softfork activates on mainnet, un-upgraded
+  miners will not accidentally violate the timewarp rule. (#31376, #31600)
+
+As a reminder, it's important that any software which uses the `getblocktemplate`
+RPC takes these values into account (either `curtime` or `mintime` is fine).
+Relying only on a clock can lead to invalid blocks under some circumstances,
+especially once a timewarp fix is deployed.

src/bitcoin-chainstate.cpp

@@ -106,6 +106,7 @@ int main(int argc, char* argv[])
     };
     auto notifications = std::make_unique<KernelNotifications>();
 
+    kernel::CacheSizes cache_sizes{DEFAULT_KERNEL_CACHE};
 
     // SETUP: Chainstate
     auto chainparams = CChainParams::Main();
@@ -119,11 +120,14 @@ int main(int argc, char* argv[])
         .chainparams = chainman_opts.chainparams,
         .blocks_dir = abs_datadir / "blocks",
         .notifications = chainman_opts.notifications,
+        .block_tree_db_params = DBParams{
+            .path = abs_datadir / "blocks" / "index",
+            .cache_bytes = cache_sizes.block_tree_db,
+        },
     };
     util::SignalInterrupt interrupt;
     ChainstateManager chainman{interrupt, chainman_opts, blockman_opts};
 
-    kernel::CacheSizes cache_sizes{DEFAULT_KERNEL_CACHE};
     node::ChainstateLoadOptions options;
     auto [status, error] = node::LoadChainstate(chainman, cache_sizes, options);
     if (status != node::ChainstateLoadStatus::SUCCESS) {

src/chain.h

@@ -35,6 +35,9 @@ static constexpr int64_t MAX_FUTURE_BLOCK_TIME = 2 * 60 * 60;
  * MAX_FUTURE_BLOCK_TIME.
  */
 static constexpr int64_t TIMESTAMP_WINDOW = MAX_FUTURE_BLOCK_TIME;
+ //! Init values for CBlockIndex nSequenceId when loaded from disk
+static constexpr int32_t SEQ_ID_BEST_CHAIN_FROM_DISK = 0;
+static constexpr int32_t SEQ_ID_INIT_FROM_DISK = 1;
 
 /**
  * Maximum gap between node time and block time used
@@ -191,7 +194,9 @@ public:
     uint32_t nNonce{0};
 
     //! (memory only) Sequential id assigned to distinguish order in which blocks are received.
-    int32_t nSequenceId{0};
+    //! Initialized to SEQ_ID_INIT_FROM_DISK{1} when loading blocks from disk, except for blocks
+    //! belonging to the best chain which overwrite it to SEQ_ID_BEST_CHAIN_FROM_DISK{0}.
+    int32_t nSequenceId{SEQ_ID_INIT_FROM_DISK};
 
     //! (memory only) Maximum nTime in the chain up to and including this block.
     unsigned int nTimeMax{0};

src/init.cpp

@@ -1057,6 +1057,10 @@ bool AppInitParameterInteraction(const ArgsManager& args)
             .chainparams = chainman_opts_dummy.chainparams,
             .blocks_dir = args.GetBlocksDirPath(),
             .notifications = chainman_opts_dummy.notifications,
+            .block_tree_db_params = DBParams{
+                .path = args.GetDataDirNet() / "blocks" / "index",
+                .cache_bytes = 0,
+            },
         };
         auto blockman_result{ApplyArgsManOptions(args, blockman_opts_dummy)};
         if (!blockman_result) {
@@ -1203,18 +1207,33 @@ static ChainstateLoadResult InitAndLoadChainstate(
         .signals = node.validation_signals.get(),
     };
     Assert(ApplyArgsManOptions(args, chainman_opts)); // no error can happen, already checked in AppInitParameterInteraction
+
     BlockManager::Options blockman_opts{
         .chainparams = chainman_opts.chainparams,
         .blocks_dir = args.GetBlocksDirPath(),
         .notifications = chainman_opts.notifications,
+        .block_tree_db_params = DBParams{
+            .path = args.GetDataDirNet() / "blocks" / "index",
+            .cache_bytes = cache_sizes.block_tree_db,
+            .wipe_data = do_reindex,
+        },
     };
     Assert(ApplyArgsManOptions(args, blockman_opts)); // no error can happen, already checked in AppInitParameterInteraction
+
+    // Creating the chainstate manager internally creates a BlockManager, opens
+    // the blocks tree db, and wipes existing block files in case of a reindex.
+    // The coinsdb is opened at a later point on LoadChainstate.
     try {
         node.chainman = std::make_unique<ChainstateManager>(*Assert(node.shutdown_signal), chainman_opts, blockman_opts);
+    } catch (dbwrapper_error& e) {
+        LogError("%s", e.what());
+        return {ChainstateLoadStatus::FAILURE, _("Error opening block database")};
     } catch (std::exception& e) {
         return {ChainstateLoadStatus::FAILURE_FATAL, Untranslated(strprintf("Failed to initialize ChainstateManager: %s", e.what()))};
     }
     ChainstateManager& chainman = *node.chainman;
+    if (chainman.m_interrupt) return {ChainstateLoadStatus::INTERRUPTED, {}};
+
     // This is defined and set here instead of inline in validation.h to avoid a hard
     // dependency between validation and index/base, since the latter is not in
     // libbitcoinkernel.
@@ -1237,7 +1256,6 @@ static ChainstateLoadResult InitAndLoadChainstate(
     };
     node::ChainstateLoadOptions options;
     options.mempool = Assert(node.mempool.get());
-    options.wipe_block_tree_db = do_reindex;
     options.wipe_chainstate_db = do_reindex || do_reindex_chainstate;
     options.prune = chainman.m_blockman.IsPruneMode();
     options.check_blocks = args.GetIntArg("-checkblocks", DEFAULT_CHECKBLOCKS);

src/interfaces/chain.h

@@ -289,6 +289,9 @@ public:
     //! Check if any block has been pruned.
     virtual bool havePruned() = 0;
 
+    //! Get the current prune height.
+    virtual std::optional<int> getPruneHeight() = 0;
+
     //! Check if the node is ready to broadcast transactions.
     virtual bool isReadyToBroadcast() = 0;
 

src/kernel/blockmanager_opts.h

@@ -5,6 +5,7 @@
 #ifndef BITCOIN_KERNEL_BLOCKMANAGER_OPTS_H
 #define BITCOIN_KERNEL_BLOCKMANAGER_OPTS_H
 
+#include <dbwrapper.h>
 #include <kernel/notifications_interface.h>
 #include <util/fs.h>
 
@@ -27,6 +28,7 @@ struct BlockManagerOpts {
     bool fast_prune{false};
     const fs::path blocks_dir;
     Notifications& notifications;
+    DBParams block_tree_db_params;
 };
 
 } // namespace kernel

src/kernel/chainstatemanager_opts.h

@@ -42,7 +42,6 @@ struct ChainstateManagerOpts {
     std::optional<uint256> assumed_valid_block{};
     //! If the tip is older than this, the node is considered to be in initial block download.
     std::chrono::seconds max_tip_age{DEFAULT_MAX_TIP_AGE};
-    DBOptions block_tree_db{};
     DBOptions coins_db{};
     CoinsViewOptions coins_view{};
     Notifications& notifications;

src/node/blockmanager_args.cpp

@@ -6,6 +6,7 @@
 
 #include <common/args.h>
 #include <node/blockstorage.h>
+#include <node/database_args.h>
 #include <tinyformat.h>
 #include <util/result.h>
 #include <util/translation.h>
@@ -34,6 +35,8 @@ util::Result<void> ApplyArgsManOptions(const ArgsManager& args, BlockManager::Op
 
     if (auto value{args.GetBoolArg("-fastprune")}) opts.fast_prune = *value;
 
+    ReadDatabaseArgs(args, opts.block_tree_db_params.options);
+
     return {};
 }
 } // namespace node

src/node/blockstorage.cpp

@@ -36,6 +36,7 @@
 #include <util/translation.h>
 #include <validation.h>
 
+#include <cstddef>
 #include <map>
 #include <ranges>
 #include <unordered_map>
@@ -158,12 +159,13 @@ bool CBlockIndexWorkComparator::operator()(const CBlockIndex* pa, const CBlockIn
     if (pa->nChainWork > pb->nChainWork) return false;
     if (pa->nChainWork < pb->nChainWork) return true;
 
-    // ... then by earliest time received, ...
+    // ... then by earliest activatable time, ...
     if (pa->nSequenceId < pb->nSequenceId) return false;
     if (pa->nSequenceId > pb->nSequenceId) return true;
 
     // Use pointer address as tie breaker (should only happen with blocks
-    // loaded from disk, as those all have id 0).
+    // loaded from disk, as those share the same id: 0 for blocks on the
+    // best chain, 1 for all others).
     if (pa < pb) return false;
     if (pa > pb) return true;
 
@@ -214,7 +216,7 @@ CBlockIndex* BlockManager::AddToBlockIndex(const CBlockHeader& block, CBlockInde
     // We assign the sequence id to blocks only when the full data is available,
     // to avoid miners withholding blocks but broadcasting headers, to get a
     // competitive advantage.
-    pindexNew->nSequenceId = 0;
+    pindexNew->nSequenceId = SEQ_ID_INIT_FROM_DISK;
 
     pindexNew->phashBlock = &((*mi).first);
     BlockMap::iterator miPrev = m_block_index.find(block.hashPrevBlock);
@@ -1169,7 +1171,19 @@ BlockManager::BlockManager(const util::SignalInterrupt& interrupt, Options opts)
       m_opts{std::move(opts)},
       m_block_file_seq{FlatFileSeq{m_opts.blocks_dir, "blk", m_opts.fast_prune ? 0x4000 /* 16kB */ : BLOCKFILE_CHUNK_SIZE}},
       m_undo_file_seq{FlatFileSeq{m_opts.blocks_dir, "rev", UNDOFILE_CHUNK_SIZE}},
-      m_interrupt{interrupt} {}
+      m_interrupt{interrupt}
+{
+    m_block_tree_db = std::make_unique<BlockTreeDB>(m_opts.block_tree_db_params);
+
+    if (m_opts.block_tree_db_params.wipe_data) {
+        m_block_tree_db->WriteReindexing(true);
+        m_blockfiles_indexed = false;
+        // If we're reindexing in prune mode, wipe away unusable block files and all undo data files
+        if (m_prune_mode) {
+            CleanupBlockRevFiles();
+        }
+    }
+}
 
 class ImportingNow
 {

src/node/chainstate.cpp

@@ -23,10 +23,7 @@
 #include <validation.h>
 
 #include <algorithm>
-#include <atomic>
 #include <cassert>
-#include <limits>
-#include <memory>
 #include <vector>
 
 using kernel::CacheSizes;
@@ -36,34 +33,8 @@ namespace node {
 // to ChainstateManager::InitializeChainstate().
 static ChainstateLoadResult CompleteChainstateInitialization(
     ChainstateManager& chainman,
-    const CacheSizes& cache_sizes,
     const ChainstateLoadOptions& options) EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
 {
-    auto& pblocktree{chainman.m_blockman.m_block_tree_db};
-    // new BlockTreeDB tries to delete the existing file, which
-    // fails if it's still open from the previous loop. Close it first:
-    pblocktree.reset();
-    try {
-        pblocktree = std::make_unique<BlockTreeDB>(DBParams{
-            .path = chainman.m_options.datadir / "blocks" / "index",
-            .cache_bytes = cache_sizes.block_tree_db,
-            .memory_only = options.block_tree_db_in_memory,
-            .wipe_data = options.wipe_block_tree_db,
-            .options = chainman.m_options.block_tree_db});
-    } catch (dbwrapper_error& err) {
-        LogError("%s\n", err.what());
-        return {ChainstateLoadStatus::FAILURE, _("Error opening block database")};
-    }
-
-    if (options.wipe_block_tree_db) {
-        pblocktree->WriteReindexing(true);
-        chainman.m_blockman.m_blockfiles_indexed = false;
-        //If we're reindexing in prune mode, wipe away unusable block files and all undo data files
-        if (options.prune) {
-            chainman.m_blockman.CleanupBlockRevFiles();
-        }
-    }
-
     if (chainman.m_interrupt) return {ChainstateLoadStatus::INTERRUPTED, {}};
 
     // LoadBlockIndex will load m_have_pruned if we've ever removed a
@@ -155,14 +126,12 @@ static ChainstateLoadResult CompleteChainstateInitialization(
         }
     }
 
-    if (!options.wipe_block_tree_db) {
-        auto chainstates{chainman.GetAll()};
-        if (std::any_of(chainstates.begin(), chainstates.end(),
-                        [](const Chainstate* cs) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { return cs->NeedsRedownload(); })) {
-            return {ChainstateLoadStatus::FAILURE, strprintf(_("Witness data for blocks after height %d requires validation. Please restart with -reindex."),
-                                                             chainman.GetConsensus().SegwitHeight)};
-        };
-    }
+    auto chainstates{chainman.GetAll()};
+    if (std::any_of(chainstates.begin(), chainstates.end(),
+                    [](const Chainstate* cs) EXCLUSIVE_LOCKS_REQUIRED(cs_main) { return cs->NeedsRedownload(); })) {
+        return {ChainstateLoadStatus::FAILURE, strprintf(_("Witness data for blocks after height %d requires validation. Please restart with -reindex."),
+                                                         chainman.GetConsensus().SegwitHeight)};
+    };
 
     // Now that chainstates are loaded and we're able to flush to
     // disk, rebalance the coins caches to desired levels based
@@ -208,7 +177,7 @@ ChainstateLoadResult LoadChainstate(ChainstateManager& chainman, const CacheSize
         }
     }
 
-    auto [init_status, init_error] = CompleteChainstateInitialization(chainman, cache_sizes, options);
+    auto [init_status, init_error] = CompleteChainstateInitialization(chainman, options);
     if (init_status != ChainstateLoadStatus::SUCCESS) {
         return {init_status, init_error};
     }
@@ -244,7 +213,7 @@ ChainstateLoadResult LoadChainstate(ChainstateManager& chainman, const CacheSize
         // for the fully validated chainstate.
         chainman.ActiveChainstate().ClearBlockIndexCandidates();
 
-        auto [init_status, init_error] = CompleteChainstateInitialization(chainman, cache_sizes, options);
+        auto [init_status, init_error] = CompleteChainstateInitialization(chainman, options);
         if (init_status != ChainstateLoadStatus::SUCCESS) {
             return {init_status, init_error};
         }

src/node/chainstate.h

@@ -22,12 +22,7 @@ namespace node {
 
 struct ChainstateLoadOptions {
     CTxMemPool* mempool{nullptr};
-    bool block_tree_db_in_memory{false};
     bool coins_db_in_memory{false};
-    // Whether to wipe the block tree database when loading it. If set, this
-    // will also set a reindexing flag so any existing block data files will be
-    // scanned and added to the database.
-    bool wipe_block_tree_db{false};
     // Whether to wipe the chainstate database when loading it. If set, this
     // will cause the chainstate database to be rebuilt starting from genesis.
     bool wipe_chainstate_db{false};

src/node/chainstatemanager_args.cpp

@@ -49,7 +49,6 @@ util::Result<void> ApplyArgsManOptions(const ArgsManager& args, ChainstateManage
 
     if (auto value{args.GetIntArg("-maxtipage")}) opts.max_tip_age = std::chrono::seconds{*value};
 
-    ReadDatabaseArgs(args, opts.block_tree_db);
     ReadDatabaseArgs(args, opts.coins_db);
     ReadCoinsViewArgs(args, opts.coins_view);
 

src/node/interfaces.cpp

@@ -46,6 +46,7 @@
 #include <policy/settings.h>
 #include <primitives/block.h>
 #include <primitives/transaction.h>
+#include <rpc/blockchain.h>
 #include <rpc/protocol.h>
 #include <rpc/server.h>
 #include <support/allocators/secure.h>
@@ -770,6 +771,11 @@ public:
         LOCK(::cs_main);
         return chainman().m_blockman.m_have_pruned;
     }
+    std::optional<int> getPruneHeight() override
+    {
+        LOCK(chainman().GetMutex());
+        return GetPruneHeight(chainman().m_blockman, chainman().ActiveChain());
+    }
     bool isReadyToBroadcast() override { return !chainman().m_blockman.LoadingBlocks() && !isInitialBlockDownload(); }
     bool isInitialBlockDownload() override
     {

src/node/miner.cpp

@@ -28,16 +28,25 @@
 #include <utility>
 
 namespace node {
+
+int64_t GetMinimumTime(const CBlockIndex* pindexPrev, const int64_t difficulty_adjustment_interval)
+{
+    int64_t min_time{pindexPrev->GetMedianTimePast() + 1};
+    // Height of block to be mined.
+    const int height{pindexPrev->nHeight + 1};
+    // Account for BIP94 timewarp rule on all networks. This makes future
+    // activation safer.
+    if (height % difficulty_adjustment_interval == 0) {
+        min_time = std::max<int64_t>(min_time, pindexPrev->GetBlockTime() - MAX_TIMEWARP);
+    }
+    return min_time;
+}
+
 int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev)
 {
     int64_t nOldTime = pblock->nTime;
-    int64_t nNewTime{std::max<int64_t>(pindexPrev->GetMedianTimePast() + 1, TicksSinceEpoch<std::chrono::seconds>(NodeClock::now()))};
-
-    // Height of block to be mined.
-    const int height{pindexPrev->nHeight + 1};
-    if (height % consensusParams.DifficultyAdjustmentInterval() == 0) {
-        nNewTime = std::max<int64_t>(nNewTime, pindexPrev->GetBlockTime() - MAX_TIMEWARP);
-    }
+    int64_t nNewTime{std::max<int64_t>(GetMinimumTime(pindexPrev, consensusParams.DifficultyAdjustmentInterval()),
+                                       TicksSinceEpoch<std::chrono::seconds>(NodeClock::now()))};
 
     if (nOldTime < nNewTime) {
         pblock->nTime = nNewTime;

src/node/miner.h

@@ -211,6 +211,13 @@ private:
     void SortForBlock(const CTxMemPool::setEntries& package, std::vector<CTxMemPool::txiter>& sortedEntries);
 };
 
+/**
+ * Get the minimum time a miner should use in the next block. This always
+ * accounts for the BIP94 timewarp rule, so does not necessarily reflect the
+ * consensus limit.
+ */
+int64_t GetMinimumTime(const CBlockIndex* pindexPrev, const int64_t difficulty_adjustment_interval);
+
 int64_t UpdateTime(CBlockHeader* pblock, const Consensus::Params& consensusParams, const CBlockIndex* pindexPrev);
 
 /** Update an old GenerateCoinbaseCommitment from CreateNewBlock after the block txs have changed */

src/rpc/mining.cpp

@@ -49,6 +49,7 @@
 using interfaces::BlockTemplate;
 using interfaces::Mining;
 using node::BlockAssembler;
+using node::GetMinimumTime;
 using node::NodeContext;
 using node::RegenerateCommitments;
 using node::UpdateTime;
@@ -674,7 +675,7 @@ static RPCHelpMan getblocktemplate()
                 {RPCResult::Type::NUM, "coinbasevalue", "maximum allowable input to coinbase transaction, including the generation award and transaction fees (in satoshis)"},
                 {RPCResult::Type::STR, "longpollid", "an id to include with a request to longpoll on an update to this template"},
                 {RPCResult::Type::STR, "target", "The hash target"},
-                {RPCResult::Type::NUM_TIME, "mintime", "The minimum timestamp appropriate for the next block time, expressed in " + UNIX_EPOCH_TIME},
+                {RPCResult::Type::NUM_TIME, "mintime", "The minimum timestamp appropriate for the next block time, expressed in " + UNIX_EPOCH_TIME + ". Adjusted for the proposed BIP94 timewarp rule."},
                 {RPCResult::Type::ARR, "mutable", "list of ways the block template may be changed",
                 {
                     {RPCResult::Type::STR, "value", "A way the block template may be changed, e.g. 'time', 'transactions', 'prevblock'"},
@@ -683,7 +684,7 @@ static RPCHelpMan getblocktemplate()
                 {RPCResult::Type::NUM, "sigoplimit", "limit of sigops in blocks"},
                 {RPCResult::Type::NUM, "sizelimit", "limit of block size"},
                 {RPCResult::Type::NUM, "weightlimit", /*optional=*/true, "limit of block weight"},
-                {RPCResult::Type::NUM_TIME, "curtime", "current timestamp in " + UNIX_EPOCH_TIME},
+                {RPCResult::Type::NUM_TIME, "curtime", "current timestamp in " + UNIX_EPOCH_TIME + ". Adjusted for the proposed BIP94 timewarp rule."},
                 {RPCResult::Type::STR, "bits", "compressed target of next block"},
                 {RPCResult::Type::NUM, "height", "The height of the next block"},
                 {RPCResult::Type::STR_HEX, "signet_challenge", /*optional=*/true, "Only on signet"},
@@ -977,7 +978,7 @@ static RPCHelpMan getblocktemplate()
     result.pushKV("coinbasevalue", (int64_t)block.vtx[0]->vout[0].nValue);
     result.pushKV("longpollid", tip.GetHex() + ToString(nTransactionsUpdatedLast));
     result.pushKV("target", hashTarget.GetHex());
-    result.pushKV("mintime", (int64_t)pindexPrev->GetMedianTimePast()+1);
+    result.pushKV("mintime", GetMinimumTime(pindexPrev, consensusParams.DifficultyAdjustmentInterval()));
     result.pushKV("mutable", std::move(aMutable));
     result.pushKV("noncerange", "00000000ffffffff");
     int64_t nSigOpLimit = MAX_BLOCK_SIGOPS_COST;

src/test/blockmanager_tests.cpp

@@ -33,6 +33,10 @@ BOOST_AUTO_TEST_CASE(blockmanager_find_block_pos)
         .chainparams = *params,
         .blocks_dir = m_args.GetBlocksDirPath(),
         .notifications = notifications,
+        .block_tree_db_params = DBParams{
+            .path = m_args.GetDataDirNet() / "blocks" / "index",
+            .cache_bytes = 0,
+        },
     };
     BlockManager blockman{*Assert(m_node.shutdown_signal), blockman_opts};
     // simulate adding a genesis block normally
@@ -140,6 +144,10 @@ BOOST_AUTO_TEST_CASE(blockmanager_flush_block_file)
         .chainparams = Params(),
         .blocks_dir = m_args.GetBlocksDirPath(),
         .notifications = notifications,
+        .block_tree_db_params = DBParams{
+            .path = m_args.GetDataDirNet() / "blocks" / "index",
+            .cache_bytes = 0,
+        },
     };
     BlockManager blockman{*Assert(m_node.shutdown_signal), blockman_opts};
 

src/test/util/setup_common.cpp

@@ -62,7 +62,6 @@
 #include <stdexcept>
 
 using namespace util::hex_literals;
-using kernel::BlockTreeDB;
 using node::ApplyArgsManOptions;
 using node::BlockAssembler;
 using node::BlockManager;
@@ -252,14 +251,14 @@ ChainTestingSetup::ChainTestingSetup(const ChainType chainType, TestOpts opts)
             .chainparams = chainman_opts.chainparams,
             .blocks_dir = m_args.GetBlocksDirPath(),
             .notifications = chainman_opts.notifications,
+            .block_tree_db_params = DBParams{
+                .path = m_args.GetDataDirNet() / "blocks" / "index",
+                .cache_bytes = m_kernel_cache_sizes.block_tree_db,
+                .memory_only = opts.block_tree_db_in_memory,
+                .wipe_data = m_args.GetBoolArg("-reindex", false),
+            },
         };
         m_node.chainman = std::make_unique<ChainstateManager>(*Assert(m_node.shutdown_signal), chainman_opts, blockman_opts);
-        LOCK(m_node.chainman->GetMutex());
-        m_node.chainman->m_blockman.m_block_tree_db = std::make_unique<BlockTreeDB>(DBParams{
-            .path = m_args.GetDataDirNet() / "blocks" / "index",
-            .cache_bytes = m_kernel_cache_sizes.block_tree_db,
-            .memory_only = true,
-        });
     };
     m_make_chainman();
 }
@@ -285,9 +284,7 @@ void ChainTestingSetup::LoadVerifyActivateChainstate()
     auto& chainman{*Assert(m_node.chainman)};
     node::ChainstateLoadOptions options;
     options.mempool = Assert(m_node.mempool.get());
-    options.block_tree_db_in_memory = m_block_tree_db_in_memory;
     options.coins_db_in_memory = m_coins_db_in_memory;
-    options.wipe_block_tree_db = m_args.GetBoolArg("-reindex", false);
     options.wipe_chainstate_db = m_args.GetBoolArg("-reindex", false) || m_args.GetBoolArg("-reindex-chainstate", false);
     options.prune = chainman.m_blockman.IsPruneMode();
     options.check_blocks = m_args.GetIntArg("-checkblocks", DEFAULT_CHECKBLOCKS);

src/test/validation_chainstatemanager_tests.cpp

@@ -393,6 +393,11 @@ struct SnapshotTestSetup : TestChain100Setup {
                 .chainparams = chainman_opts.chainparams,
                 .blocks_dir = m_args.GetBlocksDirPath(),
                 .notifications = chainman_opts.notifications,
+                .block_tree_db_params = DBParams{
+                    .path = chainman.m_options.datadir / "blocks" / "index",
+                    .cache_bytes = m_kernel_cache_sizes.block_tree_db,
+                    .memory_only = m_block_tree_db_in_memory,
+                },
             };
             // For robustness, ensure the old manager is destroyed before creating a
             // new one.

src/validation.cpp

@@ -4706,7 +4706,7 @@ bool Chainstate::LoadChainTip()
     AssertLockHeld(cs_main);
     const CCoinsViewCache& coins_cache = CoinsTip();
     assert(!coins_cache.GetBestBlock().IsNull()); // Never called when the coins view is empty
-    const CBlockIndex* tip = m_chain.Tip();
+    CBlockIndex* tip = m_chain.Tip();
 
     if (tip && tip->GetBlockHash() == coins_cache.GetBestBlock()) {
         return true;
@@ -4718,9 +4718,22 @@ bool Chainstate::LoadChainTip()
         return false;
     }
     m_chain.SetTip(*pindex);
+    tip = m_chain.Tip();
+
+    // Make sure our chain tip before shutting down scores better than any other candidate
+    // to maintain a consistent best tip over reboots
+    auto target = tip;
+    while (target) {
+        target->nSequenceId = SEQ_ID_BEST_CHAIN_FROM_DISK;
+        target = target->pprev;
+    }
+
+    // Block index candidates are loaded before the chain tip, so we need to replace this entry
+    // Otherwise the scoring will be based on the memory address location instead of the nSequenceId
+    setBlockIndexCandidates.erase(tip);
+    TryAddBlockIndexCandidate(tip);
     PruneBlockIndexCandidates();
 
-    tip = m_chain.Tip();
     LogPrintf("Loaded best chain: hashBestChain=%s height=%d date=%s progress=%f\n",
               tip->GetBlockHash().ToString(),
               m_chain.Height(),
@@ -5366,7 +5379,9 @@ void ChainstateManager::CheckBlockIndex()
                 }
             }
         }
-        if (!pindex->HaveNumChainTxs()) assert(pindex->nSequenceId <= 0); // nSequenceId can't be set positive for blocks that aren't linked (negative is used for preciousblock)
+        // nSequenceId can't be set higher than SEQ_ID_INIT_FROM_DISK{1} for blocks that aren't linked
+        // (negative is used for preciousblock, SEQ_ID_BEST_CHAIN_FROM_DISK{0} for active chain when loadeed from disk)
+        if (!pindex->HaveNumChainTxs()) assert(pindex->nSequenceId <= SEQ_ID_INIT_FROM_DISK);
         // VALID_TRANSACTIONS is equivalent to nTx > 0 for all nodes (whether or not pruning has occurred).
         // HAVE_DATA is only equivalent to nTx > 0 (or VALID_TRANSACTIONS) if no pruning has occurred.
         if (!m_blockman.m_have_pruned) {
@@ -5623,9 +5638,8 @@ double ChainstateManager::GuessVerificationProgress(const CBlockIndex* pindex) c
         return 0.0;
     }
 
-    if (!Assume(pindex->m_chain_tx_count > 0)) {
-        LogWarning("Internal bug detected: block %d has unset m_chain_tx_count (%s %s). Please report this issue here: %s\n",
-                   pindex->nHeight, CLIENT_NAME, FormatFullVersion(), CLIENT_BUGREPORT);
+    if (pindex->m_chain_tx_count == 0) {
+        LogDebug(BCLog::VALIDATION, "Block %d has unset m_chain_tx_count. Unable to estimate verification progress.\n", pindex->nHeight);
         return 0.0;
     }
 

src/validation.h

@@ -1021,8 +1021,10 @@ public:
      * Every received block is assigned a unique and increasing identifier, so we
      * know which one to give priority in case of a fork.
      */
-    /** Blocks loaded from disk are assigned id 0, so start the counter at 1. */
-    int32_t nBlockSequenceId GUARDED_BY(::cs_main) = 1;
+    /** Blocks loaded from disk are assigned id SEQ_ID_INIT_FROM_DISK{1}
+     * (SEQ_ID_BEST_CHAIN_FROM_DISK{0} if they belong to the best chain loaded from disk),
+     * so start the counter after that. **/
+    int32_t nBlockSequenceId GUARDED_BY(::cs_main) = SEQ_ID_INIT_FROM_DISK + 1;
     /** Decreasing counter (used by subsequent preciousblock calls). */
     int32_t nBlockReverseSequenceId = -1;
     /** chainwork for the last block that preciousblock has been applied to. */
@@ -1033,7 +1035,7 @@ public:
     void ResetBlockSequenceCounters() EXCLUSIVE_LOCKS_REQUIRED(::cs_main)
     {
         AssertLockHeld(::cs_main);
-        nBlockSequenceId = 1;
+        nBlockSequenceId = SEQ_ID_INIT_FROM_DISK + 1;
         nBlockReverseSequenceId = -1;
     }
 

src/wallet/rpc/backup.cpp

@@ -1745,20 +1745,27 @@ RPCHelpMan importdescriptors()
                 if (scanned_time <= GetImportTimestamp(request, now) || results.at(i).exists("error")) {
                     response.push_back(results.at(i));
                 } else {
+                    std::string error_msg{strprintf("Rescan failed for descriptor with timestamp %d. There "
+                            "was an error reading a block from time %d, which is after or within %d seconds "
+                            "of key creation, and could contain transactions pertaining to the desc. As a "
+                            "result, transactions and coins using this desc may not appear in the wallet.",
+                            GetImportTimestamp(request, now), scanned_time - TIMESTAMP_WINDOW - 1, TIMESTAMP_WINDOW)};
+                    if (pwallet->chain().havePruned()) {
+                        error_msg += strprintf(" This error could be caused by pruning or data corruption "
+                                "(see bitcoind log for details) and could be dealt with by downloading and "
+                                "rescanning the relevant blocks (see -reindex option and rescanblockchain RPC).");
+                    } else if (pwallet->chain().hasAssumedValidChain()) {
+                        error_msg += strprintf(" This error is likely caused by an in-progress assumeutxo "
+                                "background sync. Check logs or getchainstates RPC for assumeutxo background "
+                                "sync progress and try again later.");
+                    } else {
+                        error_msg += strprintf(" This error could potentially caused by data corruption. If "
+                                "the issue persists you may want to reindex (see -reindex option).");
+                    }
+
                     UniValue result = UniValue(UniValue::VOBJ);
                     result.pushKV("success", UniValue(false));
-                    result.pushKV(
-                        "error",
-                        JSONRPCError(
-                            RPC_MISC_ERROR,
-                            strprintf("Rescan failed for descriptor with timestamp %d. There was an error reading a "
-                                      "block from time %d, which is after or within %d seconds of key creation, and "
-                                      "could contain transactions pertaining to the desc. As a result, transactions "
-                                      "and coins using this desc may not appear in the wallet. This error could be "
-                                      "caused by pruning or data corruption (see bitcoind log for details) and could "
-                                      "be dealt with by downloading and rescanning the relevant blocks (see -reindex "
-                                      "option and rescanblockchain RPC).",
-                                GetImportTimestamp(request, now), scanned_time - TIMESTAMP_WINDOW - 1, TIMESTAMP_WINDOW)));
+                    result.pushKV("error", JSONRPCError(RPC_MISC_ERROR, error_msg));
                     response.push_back(std::move(result));
                 }
             }

src/wallet/rpc/transactions.cpp

@@ -6,6 +6,7 @@
 #include <key_io.h>
 #include <policy/rbf.h>
 #include <rpc/util.h>
+#include <rpc/blockchain.h>
 #include <util/vector.h>
 #include <wallet/receive.h>
 #include <wallet/rpc/util.h>
@@ -909,9 +910,15 @@ RPCHelpMan rescanblockchain()
             }
         }
 
-        // We can't rescan beyond non-pruned blocks, stop and throw an error
+        // We can't rescan unavailable blocks, stop and throw an error
         if (!pwallet->chain().hasBlocks(pwallet->GetLastBlockHash(), start_height, stop_height)) {
-            throw JSONRPCError(RPC_MISC_ERROR, "Can't rescan beyond pruned data. Use RPC call getblockchaininfo to determine your pruned height.");
+            if (pwallet->chain().havePruned() && pwallet->chain().getPruneHeight() >= start_height) {
+                throw JSONRPCError(RPC_MISC_ERROR, "Can't rescan beyond pruned data. Use RPC call getblockchaininfo to determine your pruned height.");
+            }
+            if (pwallet->chain().hasAssumedValidChain()) {
+                throw JSONRPCError(RPC_MISC_ERROR, "Failed to rescan unavailable blocks likely due to an in-progress assumeutxo background sync. Check logs or getchainstates RPC for assumeutxo background sync progress and try again later.");
+            }
+            throw JSONRPCError(RPC_MISC_ERROR, "Failed to rescan unavailable blocks, potentially caused by data corruption. If the issue persists you may want to reindex (see -reindex option).");
         }
 
         CHECK_NONFATAL(pwallet->chain().findAncestorByHeight(pwallet->GetLastBlockHash(), start_height, FoundBlock().hash(start_block)));

test/functional/feature_chain_tiebreaks.py

@@ -0,0 +1,151 @@
+#!/usr/bin/env python3
+# Copyright (c) The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test that the correct active block is chosen in complex reorgs."""
+
+from test_framework.blocktools import create_block
+from test_framework.messages import CBlockHeader
+from test_framework.p2p import P2PDataStore
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
+
+class ChainTiebreaksTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 2
+        self.setup_clean_chain = True
+
+    @staticmethod
+    def send_headers(node, blocks):
+        """Submit headers for blocks to node."""
+        for block in blocks:
+            # Use RPC rather than P2P, to prevent the message from being interpreted as a block
+            # announcement.
+            node.submitheader(hexdata=CBlockHeader(block).serialize().hex())
+
+    def test_chain_split_in_memory(self):
+        node = self.nodes[0]
+        # Add P2P connection to bitcoind
+        peer = node.add_p2p_connection(P2PDataStore())
+
+        self.log.info('Precomputing blocks')
+        #
+        #          /- B3 -- B7
+        #        B1      \- B8
+        #       /  \
+        #      /    \ B4 -- B9
+        #   B0           \- B10
+        #      \
+        #       \  /- B5
+        #        B2
+        #          \- B6
+        #
+        blocks = []
+
+        # Construct B0, building off genesis.
+        start_height = node.getblockcount()
+        blocks.append(create_block(
+            hashprev=int(node.getbestblockhash(), 16),
+            tmpl={"height": start_height + 1}
+        ))
+        blocks[-1].solve()
+
+        # Construct B1-B10.
+        for i in range(1, 11):
+            blocks.append(create_block(
+                hashprev=int(blocks[(i - 1) >> 1].hash, 16),
+                tmpl={
+                    "height": start_height + (i + 1).bit_length(),
+                    # Make sure each block has a different hash.
+                    "curtime": blocks[-1].nTime + 1,
+                }
+            ))
+            blocks[-1].solve()
+
+        self.log.info('Make sure B0 is accepted normally')
+        peer.send_blocks_and_test([blocks[0]], node, success=True)
+        # B0 must be active chain now.
+        assert_equal(node.getbestblockhash(), blocks[0].hash)
+
+        self.log.info('Send B1 and B2 headers, and then blocks in opposite order')
+        self.send_headers(node, blocks[1:3])
+        peer.send_blocks_and_test([blocks[2]], node, success=True)
+        peer.send_blocks_and_test([blocks[1]], node, success=False)
+        # B2 must be active chain now, as full data for B2 was received first.
+        assert_equal(node.getbestblockhash(), blocks[2].hash)
+
+        self.log.info('Send all further headers in order')
+        self.send_headers(node, blocks[3:])
+        # B2 is still the active chain, headers don't change this.
+        assert_equal(node.getbestblockhash(), blocks[2].hash)
+
+        self.log.info('Send blocks B7-B10')
+        peer.send_blocks_and_test([blocks[7]], node, success=False)
+        peer.send_blocks_and_test([blocks[8]], node, success=False)
+        peer.send_blocks_and_test([blocks[9]], node, success=False)
+        peer.send_blocks_and_test([blocks[10]], node, success=False)
+        # B2 is still the active chain, as B7-B10 have missing parents.
+        assert_equal(node.getbestblockhash(), blocks[2].hash)
+
+        self.log.info('Send parents B3-B4 of B8-B10 in reverse order')
+        peer.send_blocks_and_test([blocks[4]], node, success=False, force_send=True)
+        peer.send_blocks_and_test([blocks[3]], node, success=False, force_send=True)
+        # B9 is now active. Despite B7 being received earlier, the missing parent.
+        assert_equal(node.getbestblockhash(), blocks[9].hash)
+
+        self.log.info('Invalidate B9-B10')
+        node.invalidateblock(blocks[9].hash)
+        node.invalidateblock(blocks[10].hash)
+        # B7 is now active.
+        assert_equal(node.getbestblockhash(), blocks[7].hash)
+
+        # Invalidate blocks to start fresh on the next test
+        node.invalidateblock(blocks[0].hash)
+
+    def test_chain_split_from_disk(self):
+        node = self.nodes[0]
+        peer = node.add_p2p_connection(P2PDataStore())
+
+        self.log.info('Precomputing blocks')
+        #
+        #      A1
+        #     /
+        #   G
+        #     \
+        #      A2
+        #
+        blocks = []
+
+        # Construct two blocks building from genesis.
+        start_height = node.getblockcount()
+        genesis_block = node.getblock(node.getblockhash(start_height))
+        prev_time = genesis_block["time"]
+
+        for i in range(0, 2):
+            blocks.append(create_block(
+                hashprev=int(genesis_block["hash"], 16),
+                tmpl={"height": start_height + 1,
+                # Make sure each block has a different hash.
+                "curtime": prev_time + i + 1,
+                }
+            ))
+            blocks[-1].solve()
+
+        # Send blocks and test the last one is not connected
+        self.log.info('Send A1 and A2. Make sure than only the former connects')
+        peer.send_blocks_and_test([blocks[0]], node, success=True)
+        peer.send_blocks_and_test([blocks[1]], node, success=False)
+
+        self.log.info('Restart the node and check that the best tip before restarting matched the ones afterwards')
+        # Restart and check enough times to this to eventually fail if the logic is broken
+        for _ in range(10):
+            self.restart_node(0)
+            assert_equal(blocks[0].hash, node.getbestblockhash())
+
+    def run_test(self):
+        self.test_chain_split_in_memory()
+        self.test_chain_split_from_disk()
+
+
+if __name__ == '__main__':
+    ChainTiebreaksTest(__file__).main()

test/functional/mining_basic.py

@@ -153,6 +153,8 @@ class MiningTest(BitcoinTestFramework):
         # The template will have an adjusted timestamp, which we then modify
         tmpl = node.getblocktemplate(NORMAL_GBT_REQUEST_PARAMS)
         assert_greater_than_or_equal(tmpl['curtime'], t + MAX_FUTURE_BLOCK_TIME - MAX_TIMEWARP)
+        # mintime and curtime should match
+        assert_equal(tmpl['mintime'], tmpl['curtime'])
 
         block = CBlock()
         block.nVersion = tmpl["version"]

test/functional/rpc_blockchain.py

@@ -549,6 +549,7 @@ class BlockchainTest(BitcoinTestFramework):
         # The chain has probably already been restored by the time reconsiderblock returns,
         # but poll anyway.
         self.wait_until(lambda: node.waitfornewblock(timeout=100)['hash'] == current_hash)
+        assert_raises_rpc_error(-1, "Negative timeout", node.waitfornewblock, -1)
 
     def _test_waitforblockheight(self):
         self.log.info("Test waitforblockheight")

test/functional/test_runner.py

@@ -371,6 +371,7 @@ BASE_SCRIPTS = [
     'feature_includeconf.py',
     'feature_addrman.py',
     'feature_asmap.py',
+    'feature_chain_tiebreaks.py',
     'feature_fastprune.py',
     'feature_framework_miniwallet.py',
     'mempool_unbroadcast.py',

test/functional/wallet_assumeutxo.py

@@ -7,11 +7,11 @@ See feature_assumeutxo.py for background.
 
 ## Possible test improvements
 
-- TODO: test import descriptors while background sync is in progress
 - TODO: test loading a wallet (backup) on a pruned node
 
 """
 from test_framework.address import address_to_scriptpubkey
+from test_framework.descriptors import descsum_create
 from test_framework.test_framework import BitcoinTestFramework
 from test_framework.messages import COIN
 from test_framework.util import (
@@ -20,6 +20,7 @@ from test_framework.util import (
     ensure_for,
 )
 from test_framework.wallet import MiniWallet
+from test_framework.wallet_util import get_generate_key
 
 START_HEIGHT = 199
 SNAPSHOT_BASE_HEIGHT = 299
@@ -49,6 +50,13 @@ class AssumeutxoTest(BitcoinTestFramework):
         self.add_nodes(3)
         self.start_nodes(extra_args=self.extra_args)
 
+    def import_descriptor(self, node, wallet_name, key, timestamp):
+        import_request = [{"desc": descsum_create("pkh(" + key.pubkey + ")"),
+                           "timestamp": timestamp,
+                           "label": "Descriptor import test"}]
+        wrpc = node.get_wallet_rpc(wallet_name)
+        return wrpc.importdescriptors(import_request)
+
     def run_test(self):
         """
         Bring up two (disconnected) nodes, mine some new blocks on the first,
@@ -157,6 +165,21 @@ class AssumeutxoTest(BitcoinTestFramework):
         self.log.info("Backup from before the snapshot height can't be loaded during background sync")
         assert_raises_rpc_error(-4, "Wallet loading failed. Error loading wallet. Wallet requires blocks to be downloaded, and software does not currently support loading wallets while blocks are being downloaded out of order when using assumeutxo snapshots. Wallet should be able to load successfully after node sync reaches height 299", n1.restorewallet, "w2", "backup_w2.dat")
 
+        self.log.info("Test loading descriptors during background sync")
+        wallet_name = "w1"
+        n1.createwallet(wallet_name, disable_private_keys=True)
+        key = get_generate_key()
+        time = n1.getblockchaininfo()['time']
+        timestamp = 0
+        expected_error_message = f"Rescan failed for descriptor with timestamp {timestamp}. There was an error reading a block from time {time}, which is after or within 7200 seconds of key creation, and could contain transactions pertaining to the desc. As a result, transactions and coins using this desc may not appear in the wallet. This error is likely caused by an in-progress assumeutxo background sync. Check logs or getchainstates RPC for assumeutxo background sync progress and try again later."
+        result = self.import_descriptor(n1, wallet_name, key, timestamp)
+        assert_equal(result[0]['error']['code'], -1)
+        assert_equal(result[0]['error']['message'], expected_error_message)
+
+        self.log.info("Test that rescanning blocks from before the snapshot fails when blocks are not available from the background sync yet")
+        w1 = n1.get_wallet_rpc(wallet_name)
+        assert_raises_rpc_error(-1, "Failed to rescan unavailable blocks likely due to an in-progress assumeutxo background sync. Check logs or getchainstates RPC for assumeutxo background sync progress and try again later.", w1.rescanblockchain, 100)
+
         PAUSE_HEIGHT = FINAL_HEIGHT - 40
 
         self.log.info("Restarting node to stop at height %d", PAUSE_HEIGHT)
@@ -204,6 +227,11 @@ class AssumeutxoTest(BitcoinTestFramework):
         self.wait_until(lambda: len(n2.getchainstates()['chainstates']) == 1)
         ensure_for(duration=1, f=lambda: (n2.getbalance() == 34))
 
+        self.log.info("Ensuring descriptors can be loaded after background sync")
+        n1.loadwallet(wallet_name)
+        result = self.import_descriptor(n1, wallet_name, key, timestamp)
+        assert_equal(result[0]['success'], True)
+
 
 if __name__ == '__main__':
     AssumeutxoTest(__file__).main()