Allow unmarshalling ints to uints and uints to ints

Author: oschwald

decoder.go

@@ -211,6 +211,12 @@ func (d *decoder) unmarshalInt32(size uint, offset uint, result reflect.Value) (
 	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
 		result.SetInt(int64(value))
 		return newOffset, nil
+	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
+		if value < 0 {
+			return 0, fmt.Errorf("trying to unmarshal %v into %v", value, result.Type())
+		}
+		result.SetUint(uint64(value))
+		return newOffset, nil
 	case reflect.Interface:
 		result.Set(reflect.ValueOf(value))
 		return newOffset, nil
@@ -287,6 +293,9 @@ func (d *decoder) unmarshalUint(size uint, offset uint, result reflect.Value, ui
 	switch result.Kind() {
 	default:
 		return newOffset, fmt.Errorf("trying to unmarshal %v into %v", value, result.Type())
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		result.SetInt(int64(value))
+		return newOffset, nil
 	case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr:
 		result.SetUint(value)
 		return newOffset, nil

reader_test.go

@@ -155,6 +155,25 @@ func (s *MySuite) TestDecoder(c *C) {
 	}
 }
 
+func (s *MySuite) TestDecodingUint16IntoInt(c *C) {
+	reader, err := Open("test-data/test-data/MaxMind-DB-test-decoder.mmdb")
+	if err != nil {
+		c.Logf("unexpected error while opening database: %v", err)
+		c.Fail()
+	}
+
+	var result struct {
+		Uint16 int `maxminddb:"uint16"`
+	}
+	err = reader.Lookup(net.ParseIP("::1.1.1.0"), &result)
+	if err != nil {
+		c.Log(err)
+		c.Fail()
+	}
+
+	c.Assert(result.Uint16, Equals, 100)
+}
+
 func (s *MySuite) TestIpv6inIpv4(c *C) {
 	reader, err := Open("test-data/test-data/MaxMind-DB-test-ipv4-24.mmdb")
 	if err != nil {