From 94e1505ccdd6b452baa530d15b2b21b3b00ae247 Mon Sep 17 00:00:00 2001
From: fudongbai <296179868@qq.com>
Date: Wed, 14 Jul 2021 19:55:48 +0800
Subject: [PATCH] fix can not repair

---
 core/blockchain.go | 26 +++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/core/blockchain.go b/core/blockchain.go
index d627f9bf7a..be29afe3c1 100644
--- a/core/blockchain.go
+++ b/core/blockchain.go
@@ -88,7 +88,8 @@ const (
 	maxFutureBlocks     = 256
 	maxTimeFutureBlocks = 30
 	badBlockLimit       = 10
-	preLoadLimit        = 32
+	preLoadLimit        = 64
+	maxBeyondBlocks     = 2048
 
 	// BlockChainVersion ensures that an incompatible database forces a resync from scratch.
 	//
@@ -514,6 +515,7 @@ func (bc *BlockChain) SetHeadBeyondRoot(head uint64, root common.Hash) (uint64,
 		// chain reparation mechanism without deleting any data!
 		if currentBlock := bc.CurrentBlock(); currentBlock != nil && header.Number.Uint64() <= currentBlock.NumberU64() {
 			newHeadBlock := bc.GetBlock(header.Hash(), header.Number.Uint64())
+			lastBlockNum := header.Number.Uint64()
 			if newHeadBlock == nil {
 				log.Error("Gap in the chain, rewinding to genesis", "number", header.Number, "hash", header.Hash())
 				newHeadBlock = bc.genesisBlock
@@ -522,12 +524,17 @@ func (bc *BlockChain) SetHeadBeyondRoot(head uint64, root common.Hash) (uint64,
 				// keeping rewinding until we exceed the optional threshold
 				// root hash
 				beyondRoot := (root == common.Hash{}) // Flag whether we're beyond the requested root (no root, always true)
-
+				enoughBeyondCount := false
+				beyondCount := 0
 				for {
+					beyondCount++
 					// If a root threshold was requested but not yet crossed, check
 					if root != (common.Hash{}) && !beyondRoot && newHeadBlock.Root() == root {
 						beyondRoot, rootNumber = true, newHeadBlock.NumberU64()
 					}
+
+					enoughBeyondCount = beyondCount > maxBeyondBlocks
+
 					if _, err := state.New(newHeadBlock.Root(), bc.stateCache, bc.snaps); err != nil {
 						log.Trace("Block state missing, rewinding further", "number", newHeadBlock.NumberU64(), "hash", newHeadBlock.Hash())
 						if pivot == nil || newHeadBlock.NumberU64() > *pivot {
@@ -543,7 +550,20 @@ func (bc *BlockChain) SetHeadBeyondRoot(head uint64, root common.Hash) (uint64,
 							newHeadBlock = bc.genesisBlock
 						}
 					}
-					if beyondRoot || newHeadBlock.NumberU64() == 0 {
+					if beyondRoot || (enoughBeyondCount && root != common.Hash{}) || newHeadBlock.NumberU64() == 0 {
+						if enoughBeyondCount && (root != common.Hash{}) && rootNumber == 0 {
+							for {
+								lastBlockNum++
+								block := bc.GetBlockByNumber(lastBlockNum)
+								if block == nil {
+									break
+								}
+								if block.Root() == root {
+									rootNumber = block.NumberU64()
+									break
+								}
+							}
+						}
 						log.Debug("Rewound to block with state", "number", newHeadBlock.NumberU64(), "hash", newHeadBlock.Hash())
 						break
 					}