DATAMONGO-1204 - ObjectPath now uses raw id values to track resolved objects.

We now use the native id within ObjectPath for checking if a DBref has already been resolved. This is required as MongoDB Java driver 3 generation changed ObjectId.equals(…) which now performs a type check.

Original pull request: #334.
Related pull request: #288.

spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/convert/MappingMongoConverter.java

@@ -264,7 +264,8 @@ public class MappingMongoConverter extends AbstractMongoConverter implements App
 			accessor.setProperty(idProperty, idValue);
 		}
 
-		final ObjectPath currentPath = path.push(result, entity, idValue);
+		final ObjectPath currentPath = path.push(result, entity, idValue != null ? dbo.get(idProperty.getFieldName())
+				: null);
 
 		// Set properties not already set in the constructor
 		entity.doWithProperties(new PropertyHandler<MongoPersistentProperty>() {

spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/MongoTemplateTests.java

@@ -3035,7 +3035,7 @@ public class MongoTemplateTests {
 	 */
 	@Test
 	public void takesLimitIntoAccountWhenStreaming() {
-		
+
 		Person youngestPerson = new Person("John", 20);
 		Person oldestPerson = new Person("Jane", 42);
 
@@ -3049,6 +3049,31 @@ public class MongoTemplateTests {
 		assertThat(stream.hasNext(), is(false));
 	}
 
+	/**
+	 * @see DATAMONGO-1204
+	 */
+	@Test
+	public void resolvesCyclicDBRefCorrectly() {
+
+		SomeMessage message = new SomeMessage();
+		SomeContent content = new SomeContent();
+
+		template.save(message);
+		template.save(content);
+
+		message.dbrefContent = content;
+		content.dbrefMessage = message;
+
+		template.save(message);
+		template.save(content);
+
+		SomeMessage messageLoaded = template.findOne(query(where("id").is(message.id)), SomeMessage.class);
+		SomeContent contentLoaded = template.findOne(query(where("id").is(content.id)), SomeContent.class);
+
+		assertThat(messageLoaded.dbrefContent.id, is(contentLoaded.id));
+		assertThat(contentLoaded.dbrefMessage.id, is(messageLoaded.id));
+	}
+
 	static class DoucmentWithNamedIdField {
 
 		@Id String someIdKey;
@@ -3351,6 +3376,7 @@ public class MongoTemplateTests {
 		String id;
 		String text;
 		String name;
+		@org.springframework.data.mongodb.core.mapping.DBRef SomeMessage dbrefMessage;
 
 		public String getName() {
 			return name;