Ensure "excluder" is added prior to user defined type adapters/factories.

- Added test expose bad behaviour.

gson/src/main/java/com/google/gson/Gson.java

@@ -195,6 +195,9 @@ public final class Gson {
     factories.add(TypeAdapters.JSON_ELEMENT_FACTORY);
     factories.add(ObjectTypeAdapter.FACTORY);
 
+    // the excluder must precede all adapters that handle user-defined types
+    factories.add(excluder);
+
     // user's type adapters
     factories.addAll(typeAdapterFactories);
 
@@ -231,9 +234,6 @@ public final class Gson {
     factories.add(TypeAdapters.ENUM_FACTORY);
     factories.add(TypeAdapters.CLASS_FACTORY);
 
-    // the excluder must precede all adapters that handle user-defined types
-    factories.add(excluder);
-
     // type adapters for composite and user-defined types
     factories.add(new CollectionTypeAdapterFactory(constructorConstructor));
     factories.add(new MapTypeAdapterFactory(constructorConstructor, complexMapKeySerialization));
@@ -888,11 +888,11 @@ public final class Gson {
 
   @Override
   public String toString() {
-  	StringBuilder sb = new StringBuilder("{")
-  	    .append("serializeNulls:").append(serializeNulls)
+  	return new StringBuilder("{serializeNulls:")
+  	    .append(serializeNulls)
   	    .append("factories:").append(factories)
         .append(",instanceCreators:").append(constructorConstructor)
-        .append("}");
-  	return sb.toString();
+        .append("}")
+        .toString();
   }
 }

gson/src/test/java/com/google/gson/functional/ObjectTest.java

@@ -19,8 +19,12 @@ package com.google.gson.functional;
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.InstanceCreator;
+import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParseException;
+import com.google.gson.JsonSerializationContext;
+import com.google.gson.JsonSerializer;
+import com.google.gson.common.TestTypes;
 import com.google.gson.common.TestTypes.ArrayOfObjects;
 import com.google.gson.common.TestTypes.BagOfPrimitiveWrappers;
 import com.google.gson.common.TestTypes.BagOfPrimitives;
@@ -284,6 +288,21 @@ public class ObjectTest extends TestCase {
     }));
   }
 
+  public void testAnonymousLocalClassesCustomSerialization() throws Exception {
+    gson = new GsonBuilder()
+        .registerTypeHierarchyAdapter(ClassWithNoFields.class,
+            new JsonSerializer<ClassWithNoFields>() {
+              public JsonElement serialize(
+                  ClassWithNoFields src, Type typeOfSrc, JsonSerializationContext context) {
+                return new JsonObject();
+              }
+            }).create();
+
+    assertEquals("null", gson.toJson(new ClassWithNoFields() {
+      // empty anonymous class
+    }));
+  }
+
   public void testPrimitiveArrayFieldSerialization() {
     PrimitiveArray target = new PrimitiveArray(new long[] { 1L, 2L, 3L });
     assertEquals(target.getExpectedJson(), gson.toJson(target));