Add null checks before attempting debug response writing (#1840)

Author: normj

Libraries/src/Amazon.Lambda.Serialization.Json/Amazon.Lambda.Serialization.Json.csproj

@@ -9,7 +9,7 @@
     <AssemblyName>Amazon.Lambda.Serialization.Json</AssemblyName>
     <PackageId>Amazon.Lambda.Serialization.Json</PackageId>
     <PackageTags>AWS;Amazon;Lambda</PackageTags>
-    <VersionPrefix>2.2.3</VersionPrefix>
+    <VersionPrefix>2.2.4</VersionPrefix>
   </PropertyGroup>
 
   <ItemGroup>

Libraries/src/Amazon.Lambda.Serialization.Json/JsonSerializer.cs

@@ -94,7 +94,7 @@ public void Serialize<T>(T response, Stream responseStream)
         {
             try
             {
-                if (debug)
+                if (debug && response != null)
                 {
                     using (StringWriter debugWriter = new StringWriter())
                     {

Libraries/src/Amazon.Lambda.Serialization.SystemTextJson/AbstractLambdaJsonSerializer.cs

@@ -48,7 +48,7 @@ public void Serialize<T>(T response, Stream responseStream)
         {
             try
             {
-                if (_debug)
+                if (_debug && response != null)
                 {
                     using (var debugStream = new MemoryStream())
                     using (var utf8Writer = new Utf8JsonWriter(debugStream, WriterOptions))

Libraries/src/Amazon.Lambda.Serialization.SystemTextJson/Amazon.Lambda.Serialization.SystemTextJson.csproj

@@ -9,7 +9,7 @@
         <AssemblyName>Amazon.Lambda.Serialization.SystemTextJson</AssemblyName>
         <PackageId>Amazon.Lambda.Serialization.SystemTextJson</PackageId>
         <PackageTags>AWS;Amazon;Lambda</PackageTags>
-        <VersionPrefix>2.4.3</VersionPrefix>
+        <VersionPrefix>2.4.4</VersionPrefix>
 		<PackageReadmeFile>README.md</PackageReadmeFile>
     </PropertyGroup>
 	<ItemGroup>

Libraries/src/Amazon.Lambda.Serialization.SystemTextJson/LambdaJsonSerializer.cs

@@ -95,7 +95,7 @@ public void Serialize<T>(T response, Stream responseStream)
         {
             try
             {
-                if (_debug)
+                if (_debug && response != null)
                 {
                     using (var debugWriter = new StringWriter())
                     using (var utf8Writer = new Utf8JsonWriter(responseStream, WriterOptions))