From 53708e2f1536bda500ca109ad82869122b776f25 Mon Sep 17 00:00:00 2001
From: Jan Tattermusch <jtattermusch@google.com>
Date: Mon, 8 Jun 2020 17:03:03 +0200
Subject: [PATCH] test writing to a stackalloc buffer

---
 .../src/Google.Protobuf.Test/MessageParsingHelpers.cs  | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/csharp/src/Google.Protobuf.Test/MessageParsingHelpers.cs b/csharp/src/Google.Protobuf.Test/MessageParsingHelpers.cs
index fb83ff4e73..36a2f02229 100644
--- a/csharp/src/Google.Protobuf.Test/MessageParsingHelpers.cs
+++ b/csharp/src/Google.Protobuf.Test/MessageParsingHelpers.cs
@@ -127,7 +127,15 @@ namespace Google.Protobuf
                 var segmentedBufferWriter = new ArrayBufferWriter<byte>();
                 segmentedBufferWriter.MaxGrowBy = blockSize;
                 message.WriteTo(segmentedBufferWriter);
-                Assert.AreEqual(bytes, bufferWriter.WrittenSpan.ToArray());
+                Assert.AreEqual(bytes, segmentedBufferWriter.WrittenSpan.ToArray());
+            }
+
+            // if the full message is small enough, try serializing directly into stack-allocated buffer
+            if (bytes.Length <= 256)
+            {
+                Span<byte> stackAllocBuffer = stackalloc byte[bytes.Length];
+                message.WriteTo(stackAllocBuffer);
+                Assert.AreEqual(bytes, stackAllocBuffer.ToArray());
             }
         }
     }