Fix optarg handling for listtransactions and add tests.

jsoncmd.go

@@ -4391,7 +4391,7 @@ func NewListTransactionsCmd(id interface{}, optArgs ...interface{}) (*ListTransa
 		account = ac
 	}
 	if len(optArgs) > 1 {
-		cnt, ok := optArgs[0].(int)
+		cnt, ok := optArgs[1].(int)
 		if !ok {
 			return nil, errors.New("second optional argument count is not an int")
 		}
@@ -4399,7 +4399,7 @@ func NewListTransactionsCmd(id interface{}, optArgs ...interface{}) (*ListTransa
 		count = cnt
 	}
 	if len(optArgs) > 2 {
-		frm, ok := optArgs[0].(int)
+		frm, ok := optArgs[2].(int)
 		if !ok {
 			return nil, errors.New("third optional argument from is not an int")
 		}

jsoncmd_test.go

@@ -770,6 +770,54 @@ var jsoncmdtests = []struct {
 			MinConf: 1,
 		},
 	},
+	{
+		name: "basic listtransactions",
+		f: func() (Cmd, error) {
+			return NewListTransactionsCmd(float64(1))
+		},
+		result: &ListTransactionsCmd{
+			id:      float64(1),
+			Account: "",
+			Count:   10,
+			From:    0,
+		},
+	},
+	{
+		name: "listtransactions 1 optarg",
+		f: func() (Cmd, error) {
+			return NewListTransactionsCmd(float64(1), "abcde")
+		},
+		result: &ListTransactionsCmd{
+			id:      float64(1),
+			Account: "abcde",
+			Count:   10,
+			From:    0,
+		},
+	},
+	{
+		name: "listtransactions 2 optargs",
+		f: func() (Cmd, error) {
+			return NewListTransactionsCmd(float64(1), "abcde", 123)
+		},
+		result: &ListTransactionsCmd{
+			id:      float64(1),
+			Account: "abcde",
+			Count:   123,
+			From:    0,
+		},
+	},
+	{
+		name: "listtransactions 3 optargs",
+		f: func() (Cmd, error) {
+			return NewListTransactionsCmd(float64(1), "abcde", 123, 456)
+		},
+		result: &ListTransactionsCmd{
+			id:      float64(1),
+			Account: "abcde",
+			Count:   123,
+			From:    456,
+		},
+	},
 	{
 		name: "basic listunspent",
 		f: func() (Cmd, error) {