Merge pull request google#863 from nykolaslima/explicit-null-in-json

handle explicit null values in JSON

Author: inder123

proto/src/main/java/com/google/gson/protobuf/ProtoTypeAdapter.java

@@ -262,8 +262,8 @@ public GeneratedMessage deserialize(JsonElement json, Type typeOfT,
           String jsonFieldName =
               getCustSerializedName(fieldDescriptor.getOptions(), fieldDescriptor.getName());
 
-          if (jsonObject.has(jsonFieldName)) {
-            JsonElement jsonElement = jsonObject.get(jsonFieldName);
+          JsonElement jsonElement = jsonObject.get(jsonFieldName);
+          if (jsonElement != null && !jsonElement.isJsonNull()) {
             // Do not reuse jsonFieldName here, it might have a custom value
             Object fieldValue;
             if (fieldDescriptor.getType() == ENUM_TYPE) {

proto/src/test/java/com/google/gson/protobuf/functional/ProtosWithPrimitiveTypesTest.java

@@ -66,4 +66,11 @@ public void testDeserializeProto() {
     assertEquals("foo", proto.getMsg());
     assertEquals(3, proto.getCount());
   }
+
+  public void testDeserializeWithExplicitNullValue() {
+    SimpleProto proto = gson.fromJson("{msg:'foo',count:null}", SimpleProto.class);
+    assertEquals("foo", proto.getMsg());
+    assertEquals(0, proto.getCount());
+  }
+
 }