1 files changed, 60 insertions, 19 deletions

diff --git a/src/index/base.cpp b/src/index/base.cpp
index 3d3dda95b1..6fd2701e2e 100644
--- a/src/index/base.cpp
+++ b/src/index/base.cpp
@@ -4,15 +4,16 @@
 
 #include <chainparams.h>
 #include <index/base.h>
+#include <node/blockstorage.h>
 #include <node/ui_interface.h>
 #include <shutdown.h>
 #include <tinyformat.h>
-#include <util/system.h>
+#include <util/thread.h>
 #include <util/translation.h>
-#include <validation.h>
+#include <validation.h> // For g_chainman
 #include <warnings.h>
 
-constexpr char DB_BEST_BLOCK = 'B';
+constexpr uint8_t DB_BEST_BLOCK{'B'};
 
 constexpr int64_t SYNC_LOG_INTERVAL = 30; // seconds
 constexpr int64_t SYNC_LOCATOR_WRITE_INTERVAL = 30; // seconds
@@ -59,29 +60,65 @@ bool BaseIndex::Init()
     }
 
     LOCK(cs_main);
+    CChain& active_chain = m_chainstate->m_chain;
     if (locator.IsNull()) {
         m_best_block_index = nullptr;
     } else {
-        m_best_block_index = g_chainman.m_blockman.FindForkInGlobalIndex(::ChainActive(), locator);
+        m_best_block_index = m_chainstate->m_blockman.FindForkInGlobalIndex(active_chain, locator);
+    }
+    m_synced = m_best_block_index.load() == active_chain.Tip();
+    if (!m_synced) {
+        bool prune_violation = false;
+        if (!m_best_block_index) {
+            // index is not built yet
+            // make sure we have all block data back to the genesis
+            const CBlockIndex* block = active_chain.Tip();
+            while (block->pprev && (block->pprev->nStatus & BLOCK_HAVE_DATA)) {
+                block = block->pprev;
+            }
+            prune_violation = block != active_chain.Genesis();
+        }
+        // in case the index has a best block set and is not fully synced
+        // check if we have the required blocks to continue building the index
+        else {
+            const CBlockIndex* block_to_test = m_best_block_index.load();
+            if (!active_chain.Contains(block_to_test)) {
+                // if the bestblock is not part of the mainchain, find the fork
+                // and make sure we have all data down to the fork
+                block_to_test = active_chain.FindFork(block_to_test);
+            }
+            const CBlockIndex* block = active_chain.Tip();
+            prune_violation = true;
+            // check backwards from the tip if we have all block data until we reach the indexes bestblock
+            while (block_to_test && block->pprev && (block->pprev->nStatus & BLOCK_HAVE_DATA)) {
+                if (block_to_test == block) {
+                    prune_violation = false;
+                    break;
+                }
+                block = block->pprev;
+            }
+        }
+        if (prune_violation) {
+            return InitError(strprintf(Untranslated("%s best block of the index goes beyond pruned data. Please disable the index or reindex (which will download the whole blockchain again)"), GetName()));
+        }
     }
-    m_synced = m_best_block_index.load() == ::ChainActive().Tip();
     return true;
 }
 
-static const CBlockIndex* NextSyncBlock(const CBlockIndex* pindex_prev) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
+static const CBlockIndex* NextSyncBlock(const CBlockIndex* pindex_prev, CChain& chain) EXCLUSIVE_LOCKS_REQUIRED(cs_main)
 {
     AssertLockHeld(cs_main);
 
     if (!pindex_prev) {
-        return ::ChainActive().Genesis();
+        return chain.Genesis();
     }
 
-    const CBlockIndex* pindex = ::ChainActive().Next(pindex_prev);
+    const CBlockIndex* pindex = chain.Next(pindex_prev);
     if (pindex) {
         return pindex;
     }
 
-    return ::ChainActive().Next(::ChainActive().FindFork(pindex_prev));
+    return chain.Next(chain.FindFork(pindex_prev));
 }
 
 void BaseIndex::ThreadSync()
@@ -104,7 +141,7 @@ void BaseIndex::ThreadSync()
 
             {
                 LOCK(cs_main);
-                const CBlockIndex* pindex_next = NextSyncBlock(pindex);
+                const CBlockIndex* pindex_next = NextSyncBlock(pindex, m_chainstate->m_chain);
                 if (!pindex_next) {
                     m_best_block_index = pindex;
                     m_synced = true;
@@ -167,7 +204,7 @@ bool BaseIndex::Commit()
 bool BaseIndex::CommitInternal(CDBBatch& batch)
 {
     LOCK(cs_main);
-    GetDB().WriteBestBlock(batch, ::ChainActive().GetLocator(m_best_block_index));
+    GetDB().WriteBestBlock(batch, m_chainstate->m_chain.GetLocator(m_best_block_index));
     return true;
 }
 
@@ -177,6 +214,10 @@ bool BaseIndex::Rewind(const CBlockIndex* current_tip, const CBlockIndex* new_ti
     assert(current_tip->GetAncestor(new_tip->nHeight) == new_tip);
 
     // In the case of a reorg, ensure persisted block locator is not stale.
+    // Pruning has a minimum of 288 blocks-to-keep and getting the index
+    // out of sync may be possible but a users fault.
+    // In case we reorg beyond the pruned depth, ReadBlockFromDisk would
+    // throw and lead to a graceful shutdown
     m_best_block_index = new_tip;
     if (!Commit()) {
         // If commit fails, revert the best block index to avoid corruption.
@@ -239,7 +280,7 @@ void BaseIndex::ChainStateFlushed(const CBlockLocator& locator)
     const CBlockIndex* locator_tip_index;
     {
         LOCK(cs_main);
-        locator_tip_index = g_chainman.m_blockman.LookupBlockIndex(locator_tip_hash);
+        locator_tip_index = m_chainstate->m_blockman.LookupBlockIndex(locator_tip_hash);
     }
 
     if (!locator_tip_index) {
@@ -280,7 +321,7 @@ bool BaseIndex::BlockUntilSyncedToCurrentChain() const
         // Skip the queue-draining stuff if we know we're caught up with
         // ::ChainActive().Tip().
         LOCK(cs_main);
-        const CBlockIndex* chain_tip = ::ChainActive().Tip();
+        const CBlockIndex* chain_tip = m_chainstate->m_chain.Tip();
         const CBlockIndex* best_block_index = m_best_block_index.load();
         if (best_block_index->GetAncestor(chain_tip->nHeight) == chain_tip) {
             return true;
@@ -297,18 +338,18 @@ void BaseIndex::Interrupt()
     m_interrupt();
 }
 
-void BaseIndex::Start()
+bool BaseIndex::Start(CChainState& active_chainstate)
 {
+    m_chainstate = &active_chainstate;
     // Need to register this ValidationInterface before running Init(), so that
     // callbacks are not missed if Init sets m_synced to true.
     RegisterValidationInterface(this);
     if (!Init()) {
-        FatalError("%s: %s failed to initialize", __func__, GetName());
-        return;
+        return false;
     }
 
-    m_thread_sync = std::thread(&TraceThread<std::function<void()>>, GetName(),
-                                std::bind(&BaseIndex::ThreadSync, this));
+    m_thread_sync = std::thread(&util::TraceThread, GetName(), [this] { ThreadSync(); });
+    return true;
 }
 
 void BaseIndex::Stop()
@@ -325,6 +366,6 @@ IndexSummary BaseIndex::GetSummary() const
     IndexSummary summary{};
     summary.name = GetName();
     summary.synced = m_synced;
-    summary.best_block_height = m_best_block_index.load()->nHeight;
+    summary.best_block_height = m_best_block_index ? m_best_block_index.load()->nHeight : 0;
     return summary;
 }