fix block decode issue and add more nil check (#3953)

consensus/validator.go

@@ -84,7 +84,7 @@ func (consensus *Consensus) validateNewBlock(recvMsg *FBFTMessage) (*types.Block
 
 		blockObj = consensus.FBFTLog.GetBlockByHash(recvMsg.BlockHash)
 		if blockObj == nil {
-			if err := rlp.DecodeBytes(recvMsg.Block, &blockObj); err != nil {
+			if err := rlp.DecodeBytes(recvMsg.Block, blockObj); err != nil {
 				consensus.getLogger().Warn().
 					Err(err).
 					Uint64("MsgBlockNum", recvMsg.BlockNum).
@@ -157,7 +157,7 @@ func (consensus *Consensus) prepare() {
 
 // sendCommitMessages send out commit messages to leader
 func (consensus *Consensus) sendCommitMessages(blockObj *types.Block) {
-	if consensus.IsBackup() {
+	if consensus.IsBackup() || blockObj == nil {
 		return
 	}
 
@@ -269,6 +269,9 @@ func (consensus *Consensus) onPrepared(recvMsg *FBFTMessage) {
 
 	go func() {
 		// Try process future committed messages and process them in case of receiving committed before prepared
+		if blockObj == nil {
+			return
+		}
 		curBlockNum := consensus.blockNum
 		for _, committedMsg := range consensus.FBFTLog.GetNotVerifiedCommittedMessages(blockObj.NumberU64(), blockObj.Header().ViewID().Uint64(), blockObj.Hash()) {
 			if committedMsg != nil {