[release/1.4.11] core: ensure the canonical block is written before the canonical hash is set

(cherry picked from commit bb8059f6aa86d1052d7c2dd75a6985982cb278f4)

Conflicts:
	core/blockchain.go
	core/database_util.go
	core/headerchain.go
	eth/filters/filter.go

1 files changed, 8 insertions, 4 deletions

diff --git a/eth/filters/filter.go b/eth/filters/filter.go
index 469dfba4d..616184400 100644
--- a/eth/filters/filter.go
+++ b/eth/filters/filter.go
@@ -72,7 +72,11 @@ func (self *Filter) SetTopics(topics [][]common.Hash) {
 
 // Run filters logs with the current parameters set
 func (self *Filter) Find() vm.Logs {
-	latestBlock := core.GetBlock(self.db, core.GetHeadBlockHash(self.db))
+	latestHash := core.GetHeadBlockHash(self.db)
+	latestBlock := core.GetBlock(self.db, latestHash)
+	if latestBlock == nil {
+		return vm.Logs{}
+	}
 	var beginBlockNo uint64 = uint64(self.begin)
 	if self.begin == -1 {
 		beginBlockNo = latestBlock.NumberU64()
@@ -122,13 +126,13 @@ func (self *Filter) mipFind(start, end uint64, depth int) (logs vm.Logs) {
 }
 
 func (self *Filter) getLogs(start, end uint64) (logs vm.Logs) {
-	var block *types.Block
-
 	for i := start; i <= end; i++ {
+		var block *types.Block
 		hash := core.GetCanonicalHash(self.db, i)
 		if hash != (common.Hash{}) {
 			block = core.GetBlock(self.db, hash)
-		} else { // block not found
+		}
+		if block == nil { // block not found/written
 			return logs
 		}