From a63c5dfaa77411d837d9edac8ffdf6249561a1dd Mon Sep 17 00:00:00 2001
From: Gustav Behm <gustav@upvest.co>
Date: Sat, 19 May 2018 09:59:04 +0200
Subject: [PATCH] Correct FieldEncoder and FieldDecoder's behavior regarding
 zeroed uint32:s

---
 .../scala/io/protoless/fields/FieldDecoder.scala   | 11 ++++++++---
 .../scala/io/protoless/fields/FieldEncoder.scala   | 14 ++++++++++----
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/modules/core/src/main/scala/io/protoless/fields/FieldDecoder.scala b/modules/core/src/main/scala/io/protoless/fields/FieldDecoder.scala
index db61bf5..aac36b1 100644
--- a/modules/core/src/main/scala/io/protoless/fields/FieldDecoder.scala
+++ b/modules/core/src/main/scala/io/protoless/fields/FieldDecoder.scala
@@ -203,13 +203,18 @@ object FieldDecoder extends MidPriorityFieldDecoder {
     *
     * @group Utilities
     */
-  final private[protoless] def native[A](r: CIS => A, expectedType: FieldType): RepeatableFieldDecoder[A] = new RepeatableFieldDecoder[A] {
+  final private[protoless] def native[A](r: CIS => A, expectedType: FieldType, default: Option[A] = None): RepeatableFieldDecoder[A] = new RepeatableFieldDecoder[A] {
     override def fieldType: FieldType = expectedType
     override def read(input: CIS, index: Int): Result[A] = {
       val tag = readTag(input, index)
 
       // Check that the fieldNumber match the current index
-      if (tag.fieldNumber != index) Left(MissingField(index, expectedType, tag.wireType, tag.fieldNumber))
+      if (tag.fieldNumber != index) {
+        default match {
+          case Some(a) => Right(a)
+          case _ => Left(MissingField(index, expectedType, tag.wireType, tag.fieldNumber))
+        }
+      }
       // Check if the type match, except if fieldType=2 for repeatedfields
       else if (tag.wireType != 2 && tag.wireType != expectedType.getWireType) Left(WrongFieldType(expectedType, tag.fieldNumber, tag.wireType))
       // else try to decode the input
@@ -233,7 +238,7 @@ object FieldDecoder extends MidPriorityFieldDecoder {
   /**
     * @group DecodingNative
     */
-  implicit final val decodeUInt: RepeatableFieldDecoder[Int @@ Unsigned] = native(cis => tag.unsigned(cis.readUInt32()), FieldType.UINT32)
+  implicit final val decodeUInt: RepeatableFieldDecoder[Int @@ Unsigned] = native(cis => tag.unsigned(cis.readUInt32()), FieldType.UINT32, Some(tag.unsigned(0)))
 
   /**
     * @group DecodingNative
diff --git a/modules/core/src/main/scala/io/protoless/fields/FieldEncoder.scala b/modules/core/src/main/scala/io/protoless/fields/FieldEncoder.scala
index 3baf6e8..74995d3 100644
--- a/modules/core/src/main/scala/io/protoless/fields/FieldEncoder.scala
+++ b/modules/core/src/main/scala/io/protoless/fields/FieldEncoder.scala
@@ -100,7 +100,7 @@ object FieldEncoder extends MidPriorityFieldEncoder {
   /**
     * @group EncodingNative
     */
-  implicit final val encodeUnsignedInt: RepeatableFieldEncoder[Int @@ Unsigned] = native(_.writeUInt32, _.writeUInt32NoTag, FieldType.UINT32)
+  implicit final val encodeUnsignedInt: RepeatableFieldEncoder[Int @@ Unsigned] = native(_.writeUInt32, _.writeUInt32NoTag, FieldType.UINT32, Some(unsigned(0)))
 
   /**
     * @group EncodingNative
@@ -358,13 +358,19 @@ trait FieldEncoderHelpers {
     *
     * @group Utilities
     */
-  final protected def native[A](nativeWrite: COS => (Int, A) => Unit, nativeWriteRepeated: COS => A => Unit, nativeFieldType: FieldType): RepeatableFieldEncoder[A] = new RepeatableFieldEncoder[A] {
+  final protected def native[A](nativeWrite: COS => (Int, A) => Unit, nativeWriteRepeated: COS => A => Unit, nativeFieldType: FieldType, default: Option[A] = None): RepeatableFieldEncoder[A] = new RepeatableFieldEncoder[A] {
     override def write(index: Int, a: A, output: COS): Unit = {
-      nativeWrite(output)(index, a)
+      default match {
+        case Some(`a`) =>
+        case _ => nativeWrite(output)(index, a)
+      }
     }
 
     override def writeRepeated(a: A, output: COS): Unit = {
-      nativeWriteRepeated(output)(a)
+      default match {
+        case Some(`a`) =>
+        case _ => nativeWriteRepeated(output)(a)
+      }
     }
 
     override def fieldType: FieldType = nativeFieldType