fix: remove delete and dangling side chains in prunefreezer (#2582)

core/rawdb/freezer.go

@@ -541,41 +541,6 @@ func gcKvStore(db ethdb.KeyValueStore, ancients []common.Hash, first uint64, fro
 	}
 	batch.Reset()
 
-	// Step into the future and delete and dangling side chains
-	if frozen > 0 {
-		tip := frozen
-		nfdb := &nofreezedb{KeyValueStore: db}
-		for len(dangling) > 0 {
-			drop := make(map[common.Hash]struct{})
-			for _, hash := range dangling {
-				log.Debug("Dangling parent from freezer", "number", tip-1, "hash", hash)
-				drop[hash] = struct{}{}
-			}
-			children := ReadAllHashes(db, tip)
-			for i := 0; i < len(children); i++ {
-				// Dig up the child and ensure it's dangling
-				child := ReadHeader(nfdb, children[i], tip)
-				if child == nil {
-					log.Error("Missing dangling header", "number", tip, "hash", children[i])
-					continue
-				}
-				if _, ok := drop[child.ParentHash]; !ok {
-					children = append(children[:i], children[i+1:]...)
-					i--
-					continue
-				}
-				// Delete all block data associated with the child
-				log.Debug("Deleting dangling block", "number", tip, "hash", children[i], "parent", child.ParentHash)
-				DeleteBlock(batch, children[i], tip)
-			}
-			dangling = children
-			tip++
-		}
-		if err := batch.Write(); err != nil {
-			log.Crit("Failed to delete dangling side blocks", "err", err)
-		}
-	}
-
 	// Log something friendly for the user
 	context := []interface{}{
 		"blocks", frozen - first, "elapsed", common.PrettyDuration(time.Since(start)), "number", frozen - 1,