ExpectedHeaderPruningPoint fix (#1876)

* ExpectedHeaderPruningPoint fix

* Fix off by one error when iterating lowHash's selected chain

domain/consensus/factory.go

@@ -588,7 +588,7 @@ func dagStores(config *Config,
 			ghostdagDataStores[i] = ghostdagdatastore.New(prefixBucket, ghostdagDataCacheSize, preallocateCaches)
 		} else {
 			blockRelationStores[i] = blockrelationstore.New(prefixBucket, 200, false)
-			reachabilityDataStores[i] = reachabilitydatastore.New(prefixBucket, 86400, false)
+			reachabilityDataStores[i] = reachabilitydatastore.New(prefixBucket, pruningWindowSizePlusFinalityDepthForCache, false)
 			ghostdagDataStores[i] = ghostdagdatastore.New(prefixBucket, 200, false)
 		}
 	}

domain/consensus/model/interface_processes_dagtraversalmanager.go

@@ -8,7 +8,7 @@ type DAGTraversalManager interface {
 	LowestChainBlockAboveOrEqualToBlueScore(stagingArea *StagingArea, highHash *externalapi.DomainHash, blueScore uint64) (*externalapi.DomainHash, error)
 	// SelectedChildIterator should return a BlockIterator that iterates
 	// from lowHash (exclusive) to highHash (inclusive) over highHash's selected parent chain
-	SelectedChildIterator(stagingArea *StagingArea, highHash, lowHash *externalapi.DomainHash) (BlockIterator, error)
+	SelectedChildIterator(stagingArea *StagingArea, highHash, lowHash *externalapi.DomainHash, includeLowHash bool) (BlockIterator, error)
 	SelectedChild(stagingArea *StagingArea, highHash, lowHash *externalapi.DomainHash) (*externalapi.DomainHash, error)
 	AnticoneFromBlocks(stagingArea *StagingArea, tips []*externalapi.DomainHash, blockHash *externalapi.DomainHash) ([]*externalapi.DomainHash, error)
 	AnticoneFromVirtualPOV(stagingArea *StagingArea, blockHash *externalapi.DomainHash) ([]*externalapi.DomainHash, error)

domain/consensus/processes/dagtraversalmanager/selected_child_iterator.go

@@ -9,6 +9,7 @@ import (
 type selectedChildIterator struct {
 	dagTraversalManager model.DAGTraversalManager
 
+	includeLowHash    bool
 	highHash, lowHash *externalapi.DomainHash
 	current           *externalapi.DomainHash
 	err               error
@@ -21,6 +22,10 @@ func (s *selectedChildIterator) First() bool {
 		panic("Tried using a closed SelectedChildIterator")
 	}
 	s.current = s.lowHash
+	if s.includeLowHash {
+		return true
+	}
+
 	return s.Next()
 }
 
@@ -67,7 +72,9 @@ func (s *selectedChildIterator) Close() error {
 
 // SelectedChildIterator returns a BlockIterator that iterates from lowHash (exclusive) to highHash (inclusive) over
 // highHash's selected parent chain
-func (dtm *dagTraversalManager) SelectedChildIterator(stagingArea *model.StagingArea, highHash, lowHash *externalapi.DomainHash) (model.BlockIterator, error) {
+func (dtm *dagTraversalManager) SelectedChildIterator(stagingArea *model.StagingArea,
+	highHash, lowHash *externalapi.DomainHash, includeLowHash bool) (model.BlockIterator, error) {
+
 	isLowHashInSelectedParentChainOfHighHash, err := dtm.dagTopologyManager.IsInSelectedParentChainOf(
 		stagingArea, lowHash, highHash)
 	if err != nil {
@@ -79,6 +86,7 @@ func (dtm *dagTraversalManager) SelectedChildIterator(stagingArea *model.Staging
 	}
 	return &selectedChildIterator{
 		dagTraversalManager: dtm,
+		includeLowHash:      includeLowHash,
 		highHash:            highHash,
 		lowHash:             lowHash,
 		current:             lowHash,

domain/consensus/processes/pruningmanager/pruningmanager.go

@@ -219,7 +219,7 @@ func (pm *pruningManager) nextPruningPointAndCandidateByBlockHash(stagingArea *m
 	// We iterate until the selected parent of the given block, in order to allow a situation where the given block hash
 	// belongs to the virtual. This shouldn't change anything since the max blue score difference between a block and its
 	// selected parent is K, and K << pm.pruningDepth.
-	iterator, err := pm.dagTraversalManager.SelectedChildIterator(stagingArea, ghostdagData.SelectedParent(), lowHash)
+	iterator, err := pm.dagTraversalManager.SelectedChildIterator(stagingArea, ghostdagData.SelectedParent(), lowHash, true)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -1051,7 +1051,19 @@ func (pm *pruningManager) ExpectedHeaderPruningPoint(stagingArea *model.StagingA
 	}
 
 	nextOrCurrentPruningPoint := selectedParentHeader.PruningPoint()
-	if pm.finalityScore(ghostdagData.BlueScore()) > pm.finalityScore(selectedParentPruningPointHeader.BlueScore()+pm.pruningDepth) {
+	pruningPoint, err := pm.pruningStore.PruningPoint(pm.databaseContext, stagingArea)
+	if err != nil {
+		return nil, err
+	}
+
+	// If the block doesn't have the pruning in its selected chain we know for sure that it can't trigger a pruning point
+	// change (we check the selected parent to take care of the case where the block is the virtual which doesn't have reachability data).
+	hasPruningPointInItsSelectedChain, err := pm.dagTopologyManager.IsInSelectedParentChainOf(stagingArea, pruningPoint, ghostdagData.SelectedParent())
+	if err != nil {
+		return nil, err
+	}
+
+	if hasPruningPointInItsSelectedChain && pm.finalityScore(ghostdagData.BlueScore()) > pm.finalityScore(selectedParentPruningPointHeader.BlueScore()+pm.pruningDepth) {
 		var suggestedLowHash *externalapi.DomainHash
 		hasReachabilityData, err := pm.reachabilityDataStore.HasReachabilityData(pm.databaseContext, stagingArea, selectedParentHeader.PruningPoint())
 		if err != nil {

domain/consensus/processes/syncmanager/antipast.go

@@ -46,7 +46,7 @@ func (sm *syncManager) antiPastHashesBetween(stagingArea *model.StagingArea, low
 
 	// Collect all hashes by concatenating the merge-sets of all blocks between highHash and lowHash
 	blockHashes := []*externalapi.DomainHash{}
-	iterator, err := sm.dagTraversalManager.SelectedChildIterator(stagingArea, highHash, lowHash)
+	iterator, err := sm.dagTraversalManager.SelectedChildIterator(stagingArea, highHash, lowHash, false)
 	if err != nil {
 		return nil, nil, err
 	}
@@ -121,7 +121,7 @@ func (sm *syncManager) missingBlockBodyHashes(stagingArea *model.StagingArea, hi
 		return nil, err
 	}
 
-	selectedChildIterator, err := sm.dagTraversalManager.SelectedChildIterator(stagingArea, highHash, pruningPoint)
+	selectedChildIterator, err := sm.dagTraversalManager.SelectedChildIterator(stagingArea, highHash, pruningPoint, false)
 	if err != nil {
 		return nil, err
 	}