internal/ethapi: add missing output fields

- returned headers didn't include mixHash
- returned transactions didn't include signature fields
- empty transaction input was returned as "", but should be "0x"
- returned receipts didn't include the bloom filter
- "root" in receipts was missing 0x prefix

rpc/types.go

@@ -17,6 +17,8 @@
 package rpc
 
 import (
+	"bytes"
+	"encoding/hex"
 	"fmt"
 	"math"
 	"math/big"
@@ -272,3 +274,31 @@ func (bn *BlockNumber) UnmarshalJSON(data []byte) error {
 func (bn BlockNumber) Int64() int64 {
 	return (int64)(bn)
 }
+
+// HexBytes JSON-encodes as hex with 0x prefix.
+type HexBytes []byte
+
+func (b HexBytes) MarshalJSON() ([]byte, error) {
+	result := make([]byte, len(b)*2+4)
+	copy(result, `"0x`)
+	hex.Encode(result[3:], b)
+	result[len(result)-1] = '"'
+	return result, nil
+}
+
+func (b *HexBytes) UnmarshalJSON(input []byte) error {
+	if len(input) >= 2 && input[0] == '"' && input[len(input)-1] == '"' {
+		input = input[1 : len(input)-1]
+	}
+	if !bytes.HasPrefix(input, []byte("0x")) {
+		return fmt.Errorf("missing 0x prefix for hex byte array")
+	}
+	input = input[2:]
+	if len(input) == 0 {
+		*b = nil
+		return nil
+	}
+	*b = make([]byte, len(input)/2)
+	_, err := hex.Decode(*b, input)
+	return err
+}