From 3512b41c5cd024421a2048c70688c1b82f122dff Mon Sep 17 00:00:00 2001
From: Marius van der Wijden <m.vanderwijden@live.de>
Date: Wed, 3 Feb 2021 11:02:35 +0100
Subject: [PATCH] core: reset txpool state on sethead (#22247)

fixes an issue where local transactions that were included in the chain before a SetHead were rejected if resubmitted, since the txpool had not reset the state to the current (older) state.
---
 core/tx_pool.go | 59 +++++++++++++++++++++++++------------------------
 1 file changed, 30 insertions(+), 29 deletions(-)

diff --git a/core/tx_pool.go b/core/tx_pool.go
index 4a17c31ca8..36546cde75 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -1137,44 +1137,45 @@ func (pool *TxPool) reset(oldHead, newHead *types.Header) {
 				// head from the chain.
 				// If that is the case, we don't have the lost transactions any more, and
 				// there's nothing to add
-				if newNum < oldNum {
-					// If the reorg ended up on a lower number, it's indicative of setHead being the cause
-					log.Debug("Skipping transaction reset caused by setHead",
-						"old", oldHead.Hash(), "oldnum", oldNum, "new", newHead.Hash(), "newnum", newNum)
-				} else {
+				if newNum >= oldNum {
 					// If we reorged to a same or higher number, then it's not a case of setHead
 					log.Warn("Transaction pool reset with missing oldhead",
 						"old", oldHead.Hash(), "oldnum", oldNum, "new", newHead.Hash(), "newnum", newNum)
-				}
-				return
-			}
-			for rem.NumberU64() > add.NumberU64() {
-				discarded = append(discarded, rem.Transactions()...)
-				if rem = pool.chain.GetBlock(rem.ParentHash(), rem.NumberU64()-1); rem == nil {
-					log.Error("Unrooted old chain seen by tx pool", "block", oldHead.Number, "hash", oldHead.Hash())
 					return
 				}
-			}
-			for add.NumberU64() > rem.NumberU64() {
-				included = append(included, add.Transactions()...)
-				if add = pool.chain.GetBlock(add.ParentHash(), add.NumberU64()-1); add == nil {
-					log.Error("Unrooted new chain seen by tx pool", "block", newHead.Number, "hash", newHead.Hash())
-					return
+				// If the reorg ended up on a lower number, it's indicative of setHead being the cause
+				log.Debug("Skipping transaction reset caused by setHead",
+					"old", oldHead.Hash(), "oldnum", oldNum, "new", newHead.Hash(), "newnum", newNum)
+				// We still need to update the current state s.th. the lost transactions can be readded by the user
+			} else {
+				for rem.NumberU64() > add.NumberU64() {
+					discarded = append(discarded, rem.Transactions()...)
+					if rem = pool.chain.GetBlock(rem.ParentHash(), rem.NumberU64()-1); rem == nil {
+						log.Error("Unrooted old chain seen by tx pool", "block", oldHead.Number, "hash", oldHead.Hash())
+						return
+					}
 				}
-			}
-			for rem.Hash() != add.Hash() {
-				discarded = append(discarded, rem.Transactions()...)
-				if rem = pool.chain.GetBlock(rem.ParentHash(), rem.NumberU64()-1); rem == nil {
-					log.Error("Unrooted old chain seen by tx pool", "block", oldHead.Number, "hash", oldHead.Hash())
-					return
+				for add.NumberU64() > rem.NumberU64() {
+					included = append(included, add.Transactions()...)
+					if add = pool.chain.GetBlock(add.ParentHash(), add.NumberU64()-1); add == nil {
+						log.Error("Unrooted new chain seen by tx pool", "block", newHead.Number, "hash", newHead.Hash())
+						return
+					}
 				}
-				included = append(included, add.Transactions()...)
-				if add = pool.chain.GetBlock(add.ParentHash(), add.NumberU64()-1); add == nil {
-					log.Error("Unrooted new chain seen by tx pool", "block", newHead.Number, "hash", newHead.Hash())
-					return
+				for rem.Hash() != add.Hash() {
+					discarded = append(discarded, rem.Transactions()...)
+					if rem = pool.chain.GetBlock(rem.ParentHash(), rem.NumberU64()-1); rem == nil {
+						log.Error("Unrooted old chain seen by tx pool", "block", oldHead.Number, "hash", oldHead.Hash())
+						return
+					}
+					included = append(included, add.Transactions()...)
+					if add = pool.chain.GetBlock(add.ParentHash(), add.NumberU64()-1); add == nil {
+						log.Error("Unrooted new chain seen by tx pool", "block", newHead.Number, "hash", newHead.Hash())
+						return
+					}
 				}
+				reinject = types.TxDifference(discarded, included)
 			}
-			reinject = types.TxDifference(discarded, included)
 		}
 	}
 	// Initialize the internal state to the current head