fix string array unpack bug in accounts/abi (#18364)

accounts/abi/argument.go

@@ -202,7 +202,7 @@ func (arguments Arguments) UnpackValues(data []byte) ([]interface{}, error) {
 	virtualArgs := 0
 	for index, arg := range arguments.NonIndexed() {
 		marshalledValue, err := toGoType((index+virtualArgs)*32, arg.Type, data)
-		if arg.Type.T == ArrayTy {
+		if arg.Type.T == ArrayTy && (*arg.Type.Elem).T != StringTy {
 			// If we have a static array, like [3]uint256, these are coded as
 			// just like uint256,uint256,uint256.
 			// This means that we need to add two 'virtual' arguments when

accounts/abi/unpack.go

@@ -195,8 +195,15 @@ func toGoType(index int, t Type, output []byte) (interface{}, error) {
 
 	switch t.T {
 	case SliceTy:
+		if (*t.Elem).T == StringTy {
+			return forEachUnpack(t, output[begin:], 0, end)
+		}
 		return forEachUnpack(t, output, begin, end)
 	case ArrayTy:
+		if (*t.Elem).T == StringTy {
+			offset := int64(binary.BigEndian.Uint64(returnOutput[len(returnOutput)-8:]))
+			return forEachUnpack(t, output[offset:], 0, t.Size)
+		}
 		return forEachUnpack(t, output, index, t.Size)
 	case StringTy: // variable arrays are written at the end of the return bytes
 		return string(output[begin : begin+end]), nil

accounts/abi/unpack_test.go

@@ -241,6 +241,16 @@ var unpackTests = []unpackTest{
 		enc:  "000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000003",
 		want: [3]*big.Int{big.NewInt(1), big.NewInt(2), big.NewInt(3)},
 	},
+	{
+		def:  `[{"type": "string[4]"}]`,
+		enc:  "0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000008000000000000000000000000000000000000000000000000000000000000000c000000000000000000000000000000000000000000000000000000000000001000000000000000000000000000000000000000000000000000000000000000140000000000000000000000000000000000000000000000000000000000000000548656c6c6f0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000005576f726c64000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000b476f2d657468657265756d0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000008457468657265756d000000000000000000000000000000000000000000000000",
+		want: [4]string{"Hello", "World", "Go-ethereum", "Ethereum"},
+	},
+	{
+		def:  `[{"type": "string[]"}]`,
+		enc:  "00000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000008457468657265756d000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000b676f2d657468657265756d000000000000000000000000000000000000000000",
+		want: []string{"Ethereum", "go-ethereum"},
+	},
 	{
 		def:  `[{"type": "int8[]"}]`,
 		enc:  "0000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000000000000000000000000000000000002",
@@ -516,6 +526,57 @@ func TestMultiReturnWithArray(t *testing.T) {
 	}
 }
 
+func TestMultiReturnWithStringArray(t *testing.T) {
+	const definition = `[{"name" : "multi", "outputs": [{"name": "","type": "uint256[3]"},{"name": "","type": "address"},{"name": "","type": "string[2]"},{"name": "","type": "bool"}]}]`
+	abi, err := JSON(strings.NewReader(definition))
+	if err != nil {
+		t.Fatal(err)
+	}
+	buff := new(bytes.Buffer)
+	buff.Write(common.Hex2Bytes("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"))
+	temp, _ := big.NewInt(0).SetString("30000000000000000000", 10)
+	ret1, ret1Exp := new([3]*big.Int), [3]*big.Int{big.NewInt(1545304298), big.NewInt(6), temp}
+	ret2, ret2Exp := new(common.Address), common.HexToAddress("ab1257528b3782fb40d7ed5f72e624b744dffb2f")
+	ret3, ret3Exp := new([2]string), [2]string{"Ethereum", "Hello, Ethereum!"}
+	ret4, ret4Exp := new(bool), false
+	if err := abi.Unpack(&[]interface{}{ret1, ret2, ret3, ret4}, "multi", buff.Bytes()); err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(*ret1, ret1Exp) {
+		t.Error("big.Int array result", *ret1, "!= Expected", ret1Exp)
+	}
+	if !reflect.DeepEqual(*ret2, ret2Exp) {
+		t.Error("address result", *ret2, "!= Expected", ret2Exp)
+	}
+	if !reflect.DeepEqual(*ret3, ret3Exp) {
+		t.Error("string array result", *ret3, "!= Expected", ret3Exp)
+	}
+	if !reflect.DeepEqual(*ret4, ret4Exp) {
+		t.Error("bool result", *ret4, "!= Expected", ret4Exp)
+	}
+}
+
+func TestMultiReturnWithStringSlice(t *testing.T) {
+	const definition = `[{"name" : "multi", "outputs": [{"name": "","type": "string[]"},{"name": "","type": "uint256[]"}]}]`
+	abi, err := JSON(strings.NewReader(definition))
+	if err != nil {
+		t.Fatal(err)
+	}
+	buff := new(bytes.Buffer)
+	buff.Write(common.Hex2Bytes("000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000001200000000000000000000000000000000000000000000000000000000000000002000000000000000000000000000000000000000000000000000000000000004000000000000000000000000000000000000000000000000000000000000000800000000000000000000000000000000000000000000000000000000000000008657468657265756d000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000b676f2d657468657265756d000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000640000000000000000000000000000000000000000000000000000000000000065"))
+	ret1, ret1Exp := new([]string), []string{"ethereum", "go-ethereum"}
+	ret2, ret2Exp := new([]*big.Int), []*big.Int{big.NewInt(100), big.NewInt(101)}
+	if err := abi.Unpack(&[]interface{}{ret1, ret2}, "multi", buff.Bytes()); err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(*ret1, ret1Exp) {
+		t.Error("string slice result", *ret1, "!= Expected", ret1Exp)
+	}
+	if !reflect.DeepEqual(*ret2, ret2Exp) {
+		t.Error("uint256 slice result", *ret2, "!= Expected", ret2Exp)
+	}
+}
+
 func TestMultiReturnWithDeeplyNestedArray(t *testing.T) {
 	// Similar to TestMultiReturnWithArray, but with a special case in mind:
 	//  values of nested static arrays count towards the size as well, and any element following