Merge pull request #232 from ethpandaops/pk910/purge-parent-fork-ids-…

…cache

fix fork detection for forks starting before the finalized checkpoint

indexer/beacon/forkdetection.go

@@ -98,6 +98,18 @@ func (cache *forkCache) processBlock(block *Block) error {
 			otherChildren = append(otherChildren, child)
 		}
 
+		if parentIsFinalized {
+			// parent is finalized, so blocks building on top of it might be finalized as well.
+			// check if we have other finalized blocks building on top of the parent in the database
+			for _, child := range db.GetSlotsByParentRoot((*parentRoot)[:]) {
+				if bytes.Equal(child.Root, block.Root[:]) {
+					continue
+				}
+
+				otherChildren = append(otherChildren, newBlock(cache.indexer.dynSsz, phase0.Root(child.Root), phase0.Slot(child.Slot)))
+			}
+		}
+
 		if len(otherChildren) > 0 {
 			logbuf := strings.Builder{}
 
@@ -227,6 +239,9 @@ func (cache *forkCache) processBlock(block *Block) error {
 
 	// persist new forks and updated blocks to the database
 	if len(newForks) > 0 || len(updatedBlocks) > 0 {
+		// purge parent ids cache as the fork id tree has changed
+		cache.parentIdsCache.Purge()
+
 		err := db.RunDBTransaction(func(tx *sqlx.Tx) error {
 			// helper function to update unfinalized block fork ids in batches
 			updateUnfinalizedBlockForkIds := func(updateRoots [][]byte, forkId ForkKey) error {