From 4418e4ea6a9b8d648bcb7e7241b887cbab6936bc Mon Sep 17 00:00:00 2001
From: Taylor Gerring <taylor.gerring@gmail.com>
Date: Thu, 12 Mar 2015 08:42:31 -0500
Subject: [PATCH] Should on empty params #466

---
 rpc/args.go      | 26 +++++++++++++++++++++++++-
 rpc/args_test.go | 21 +++++++++++++++++++++
 2 files changed, 46 insertions(+), 1 deletion(-)

diff --git a/rpc/args.go b/rpc/args.go
index 2e4e2c7a95..40f8575b26 100644
--- a/rpc/args.go
+++ b/rpc/args.go
@@ -188,10 +188,34 @@ type GetBalanceArgs struct {
 }
 
 func (args *GetBalanceArgs) UnmarshalJSON(b []byte) (err error) {
-	if err = UnmarshalRawMessages(b, &args.Address, &args.BlockNumber); err != nil {
+	var obj []interface{}
+	r := bytes.NewReader(b)
+	if err := json.NewDecoder(r).Decode(&obj); err != nil {
 		return errDecodeArgs
 	}
 
+	if len(obj) < 1 {
+		return errArguments
+	}
+
+	addstr, ok := obj[0].(string)
+	if !ok {
+		return errDecodeArgs
+	}
+	args.Address = addstr
+
+	if len(obj) > 1 {
+		if obj[1].(string) == "latest" {
+			args.BlockNumber = -1
+		} else {
+			args.BlockNumber = ethutil.Big(obj[1].(string)).Int64()
+		}
+	}
+
+	// if err = UnmarshalRawMessages(b, &args.Address, &args.BlockNumber); err != nil {
+	// 	return errDecodeArgs
+	// }
+
 	return nil
 }
 
diff --git a/rpc/args_test.go b/rpc/args_test.go
index 6650d8d61f..6b6d3c3c07 100644
--- a/rpc/args_test.go
+++ b/rpc/args_test.go
@@ -43,6 +43,17 @@ func TestGetBalanceArgs(t *testing.T) {
 	}
 }
 
+func TestGetBalanceEmptyArgs(t *testing.T) {
+	input := `[]`
+
+	args := new(GetBalanceArgs)
+	err := json.Unmarshal([]byte(input), &args)
+	if err == nil {
+		t.Error("Expected error but didn't get one")
+	}
+
+}
+
 func TestGetBlockByHashArgs(t *testing.T) {
 	input := `["0xe670ec64341771606e55d6b4ca35a1a6b75ee3d5145a99d05921026d1527331", true]`
 	expected := new(GetBlockByHashArgs)
@@ -418,6 +429,16 @@ func TestFilterStringArgs(t *testing.T) {
 	}
 }
 
+func TestFilterStringEmptyArgs(t *testing.T) {
+	input := `[]`
+
+	args := new(FilterStringArgs)
+	err := json.Unmarshal([]byte(input), &args)
+	if err == nil {
+		t.Error("Expected error but didn't get one")
+	}
+}
+
 func TestWhisperIdentityArgs(t *testing.T) {
 	input := `["0xc931d93e97ab07fe42d923478ba2465f283"]`
 	expected := new(WhisperIdentityArgs)