From d81f0f0cbe4e6146d69e013a6e5d648f7234b734 Mon Sep 17 00:00:00 2001
From: Joey Yakimowich-Payne <jyapayne@gmail.com>
Date: Sat, 4 Apr 2020 07:38:14 -0600
Subject: [PATCH] Empty objects should not be encoded

---
 protobuf_serialization.nim   |  8 ++++----
 tests/test_serialization.nim | 25 +++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/protobuf_serialization.nim b/protobuf_serialization.nim
index 32489f3..bfe06cb 100644
--- a/protobuf_serialization.nim
+++ b/protobuf_serialization.nim
@@ -112,8 +112,6 @@ proc encodeField*(protobuf: var ProtoBuffer, fieldNum: int, value: SomeLengthDel
 proc put(stream: OutputStreamVar, value: object) {.inline.}
 
 proc encodeField(stream: OutputStreamVar, fieldNum: int, value: object) {.inline.} =
-  stream.append protoHeader(fieldNum, LengthDelimited)
-
   # This is currently needed in order to get the size
   # of the output before adding it to the stream.
   # Maybe there is a better way to do this
@@ -121,8 +119,10 @@ proc encodeField(stream: OutputStreamVar, fieldNum: int, value: object) {.inline
   objStream.put(value)
 
   let objOutput = objStream.getOutput()
-  stream.put(len(objOutput).uint)
-  stream.put(objOutput)
+  if objOutput.len > 0:
+    stream.append protoHeader(fieldNum, LengthDelimited)
+    stream.put(len(objOutput).uint)
+    stream.put(objOutput)
 
 proc encodeField*(protobuf: var ProtoBuffer, value: object) {.inline.} =
   protobuf.outstream.encodeField(protobuf.fieldNum, value)
diff --git a/tests/test_serialization.nim b/tests/test_serialization.nim
index 0247586..87a4fbe 100644
--- a/tests/test_serialization.nim
+++ b/tests/test_serialization.nim
@@ -116,4 +116,29 @@ suite "Test Varint Encoding":
 
     var output = proto.output
     let decoded = output.decode(Test3)
+
+    assert decoded == obj
+
+  test "Empty object field does not get encoded":
+    var proto = newProtoBuffer()
+
+    let obj = Test1()
+    proto.encodeField(1, obj)
+
+    var output = proto.output
+    assert output.len == 0
+
+    let decoded = output.decode(Test1)
+    assert decoded == obj
+
+  test "Empty object does not get encoded":
+    var proto = newProtoBuffer()
+
+    let obj = Test1()
+    proto.encode(obj)
+
+    var output = proto.output
+    assert output.len == 0
+
+    let decoded = output.decode(Test1)
     assert decoded == obj
\ No newline at end of file