From a48a51457013b61b037de3f30a692eb3bf8678fa Mon Sep 17 00:00:00 2001
From: Knut Ahlers <knut@ahlers.me>
Date: Tue, 24 Dec 2019 15:00:16 +0100
Subject: [PATCH] Support parsing left out attributes

Signed-off-by: Knut Ahlers <knut@ahlers.me>
---
 genericUnmarshaller.go | 8 ++++++--
 helpers.go             | 4 ++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/genericUnmarshaller.go b/genericUnmarshaller.go
index 4e3c3fd..30d0574 100644
--- a/genericUnmarshaller.go
+++ b/genericUnmarshaller.go
@@ -85,7 +85,7 @@ func genericUnmarshal(in []byte, out interface{}, unit *Unit) error {
 
 		case reflect.Int, reflect.Int64:
 			bv := getSingleValue(in, attributeName)
-			if isNilValue(bv) {
+			if isNilValue(bv) || len(bv) == 0 {
 				continue
 			}
 			v, err := strconv.ParseInt(string(bv), 10, 64)
@@ -164,7 +164,7 @@ func genericUnmarshal(in []byte, out interface{}, unit *Unit) error {
 
 			case reflect.Int64:
 				bv := getSingleValue(in, attributeName)
-				if !isNilValue(bv) {
+				if !isNilValue(bv) && len(bv) > 0 {
 					v, err := strconv.ParseInt(string(bv), 10, 64)
 					if err != nil {
 						return errors.Wrapf(err, "Unable to parse int for attribute %q", attributeName)
@@ -260,6 +260,10 @@ func genericUnmarshal(in []byte, out interface{}, unit *Unit) error {
 			case reflect.Int64:
 				var v []int64
 				for _, bv := range ba {
+					if len(bv) == 0 {
+						v = append(v, 0)
+						continue
+					}
 					pbv, err := strconv.ParseInt(string(bv), 10, 64)
 					if err != nil {
 						return errors.Wrapf(err, "Unable to parse int for attribute %q", attributeName)
diff --git a/helpers.go b/helpers.go
index 83d530d..a34aa77 100644
--- a/helpers.go
+++ b/helpers.go
@@ -33,6 +33,10 @@ func float2sii(f float32) ([]byte, error) {
 }
 
 func sii2float(f []byte) (float32, error) {
+	if len(f) == 0 {
+		return 0, nil
+	}
+
 	if f[0] != '&' {
 		out, err := strconv.ParseFloat(string(f), 32)
 		return float32(out), err