fix get tx by index

Author: HuangYi

rpc/namespaces/ethereum/eth/api.go

@@ -752,7 +752,7 @@ func (e *PublicAPI) getTransactionByBlockAndIndex(block *tmrpctypes.ResultBlock,
 			return nil, fmt.Errorf("failed to parse tx events: %d, %v", idx, err)
 		}
 
-		parsedTx := parsedTxs.GetTxByIndex(int(idx))
+		parsedTx := parsedTxs.GetTxByTxIndex(int(idx))
 		if parsedTx == nil {
 			return nil, fmt.Errorf("ethereum tx not found in msgs: %d", idx)
 		}

rpc/types/events.go

@@ -155,14 +155,25 @@ func (p *ParsedTxs) GetTxByHash(hash common.Hash) *ParsedTx {
 	return nil
 }
 
-// GetTxByIndex returns ParsedTx by index
-func (p *ParsedTxs) GetTxByIndex(i int) *ParsedTx {
-	if i >= len(p.Txs) {
+// GetTxByMsgIndex returns ParsedTx by msg index
+func (p *ParsedTxs) GetTxByMsgIndex(i int) *ParsedTx {
+	if i < 0 || i >= len(p.Txs) {
 		return nil
 	}
 	return &p.Txs[i]
 }
 
+// GetTxByTxIndex returns ParsedTx by tx index
+func (p *ParsedTxs) GetTxByTxIndex(i int) *ParsedTx {
+	// assuming the `EthTxIndex` continuously increment.
+	if len(p.Txs) == 0 {
+		return nil
+	}
+	msgIndex := i - int(p.Txs[0].EthTxIndex)
+	// GetTxByMsgIndex will check the bound
+	return p.GetTxByMsgIndex(msgIndex)
+}
+
 // AccumulativeGasUsed calculate the accumulated gas used within the batch
 func (p *ParsedTxs) AccumulativeGasUsed(msgIndex int) (result uint64) {
 	for i := 0; i <= msgIndex; i++ {