Merge PR #1534: Check new rat decimal string length

types/rational.go

@@ -41,6 +41,10 @@ func NewRat(Numerator int64, Denominator ...int64) Rat {
 // precision is the number of values after the decimal point which should be read
 func NewRatFromDecimal(decimalStr string, prec int) (f Rat, err Error) {
 	// first extract any negative symbol
+	if len(decimalStr) == 0 {
+		return f, ErrUnknownRequest("decimal string is empty")
+	}
+
 	neg := false
 	if string(decimalStr[0]) == "-" {
 		neg = true

types/rational_test.go

@@ -27,6 +27,7 @@ func TestNewFromDecimal(t *testing.T) {
 		expErr     bool
 		exp        Rat
 	}{
+		{"", true, Rat{}},
 		{"0", false, NewRat(0)},
 		{"1", false, NewRat(1)},
 		{"1.1", false, NewRat(11, 10)},