internal/ethapi: support "input" in transaction args

The tx data field is called "input" in returned objects and "data" in
argument objects. Make it so "input" can be used in args, but bail if
both "input" and "data" are set.

Fixes #15628

internal/ethapi/api.go

@@ -17,6 +17,7 @@
 package ethapi
 
 import (
+	"bytes"
 	"context"
 	"errors"
 	"fmt"
@@ -1067,8 +1068,11 @@ type SendTxArgs struct {
 	Gas      *hexutil.Big    `json:"gas"`
 	GasPrice *hexutil.Big    `json:"gasPrice"`
 	Value    *hexutil.Big    `json:"value"`
-	Data     hexutil.Bytes   `json:"data"`
 	Nonce    *hexutil.Uint64 `json:"nonce"`
+	// We accept "data" and "input" for backwards-compatibility reasons. "input" is the
+	// newer name and should be preferred by clients.
+	Data  *hexutil.Bytes `json:"data"`
+	Input *hexutil.Bytes `json:"input"`
 }
 
 // setDefaults is a helper function that fills in default values for unspecified tx fields.
@@ -1093,14 +1097,23 @@ func (args *SendTxArgs) setDefaults(ctx context.Context, b Backend) error {
 		}
 		args.Nonce = (*hexutil.Uint64)(&nonce)
 	}
+	if args.Data != nil && args.Input != nil && !bytes.Equal(*args.Data, *args.Input) {
+		return errors.New(`Both "data" and "input" are set and not equal. Please use "input" to pass transaction call data.`)
+	}
 	return nil
 }
 
 func (args *SendTxArgs) toTransaction() *types.Transaction {
+	var input []byte
+	if args.Data != nil {
+		input = *args.Data
+	} else if args.Input != nil {
+		input = *args.Input
+	}
 	if args.To == nil {
-		return types.NewContractCreation(uint64(*args.Nonce), (*big.Int)(args.Value), (*big.Int)(args.Gas), (*big.Int)(args.GasPrice), args.Data)
+		return types.NewContractCreation(uint64(*args.Nonce), (*big.Int)(args.Value), (*big.Int)(args.Gas), (*big.Int)(args.GasPrice), input)
 	}
-	return types.NewTransaction(uint64(*args.Nonce), *args.To, (*big.Int)(args.Value), (*big.Int)(args.Gas), (*big.Int)(args.GasPrice), args.Data)
+	return types.NewTransaction(uint64(*args.Nonce), *args.To, (*big.Int)(args.Value), (*big.Int)(args.Gas), (*big.Int)(args.GasPrice), input)
 }
 
 // submitTransaction is a helper function that submits tx to txPool and logs a message.