fix: correct numeric string coercion with leading zeros

_glua-tests/issues.lua

@@ -490,3 +490,10 @@ function test()
   assert(b == nil)
 end
 test()
+
+-- issue #478
+function test()
+  local a = "00001" + "00011"
+  assert(a == 12)
+end
+test()

state_test.go

@@ -276,6 +276,28 @@ func TestConcat(t *testing.T) {
 	errorIfNotEqual(t, "a1c", L.Concat(LString("a"), LNumber(1), LString("c")))
 }
 
+func TestDoStringNumericStringCoercion(t *testing.T) {
+	L := NewState()
+	defer L.Close()
+
+	err := L.DoString(`a = "00001" + "00011"`)
+	errorIfNotNil(t, err)
+
+	v := L.GetGlobal("a")
+	errorIfNotEqual(t, LNumber(12), v)
+}
+
+func TestDoStringNumericStringHexCoercion(t *testing.T) {
+	L := NewState()
+	defer L.Close()
+
+	err := L.DoString(`a = "0x7d6" + "1"`)
+	errorIfNotNil(t, err)
+
+	v := L.GetGlobal("a")
+	errorIfNotEqual(t, LNumber(2007), v)
+}
+
 func TestPCall(t *testing.T) {
 	L := NewState()
 	defer L.Close()

utils.go

@@ -143,14 +143,26 @@ func isArrayKey(v LNumber) bool {
 func parseNumber(number string) (LNumber, error) {
 	var value LNumber
 	number = strings.Trim(number, " \t\n")
-	if v, err := strconv.ParseInt(number, 0, LNumberBit); err != nil {
-		if v2, err2 := strconv.ParseFloat(number, LNumberBit); err2 != nil {
-			return LNumber(0), err2
-		} else {
-			value = LNumber(v2)
+	if v, err := strconv.ParseInt(number, 10, LNumberBit); err == nil {
+		value = LNumber(v)
+		return value, nil
+	}
+	if len(number) > 2 {
+		prefix := number
+		if number[0] == '+' || number[0] == '-' {
+			prefix = number[1:]
+		}
+		if strings.HasPrefix(prefix, "0x") || strings.HasPrefix(prefix, "0X") {
+			if v, err := strconv.ParseInt(number, 0, LNumberBit); err == nil {
+				value = LNumber(v)
+				return value, nil
+			}
 		}
+	}
+	if v2, err := strconv.ParseFloat(number, LNumberBit); err != nil {
+		return LNumber(0), err
 	} else {
-		value = LNumber(v)
+		value = LNumber(v2)
 	}
 	return value, nil
 }