DATAMONGO-562 - Saving versioned entity with already set id now works.

Instead of inspecting the id property we now assume the version property unset for initialization and work from there.

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

@@ -760,10 +760,11 @@ public class MongoTemplate implements MongoOperations, ApplicationContextAware {
 				this.mongoConverter.getConversionService());
 		MongoPersistentProperty idProperty = entity.getIdProperty();
 		MongoPersistentProperty versionProperty = entity.getVersionProperty();
-		Object id = beanWrapper.getProperty(idProperty);
+
+		Number version = beanWrapper.getProperty(versionProperty, Number.class, !versionProperty.usePropertyAccess());
 
 		// Fresh instance -> initialize version property
-		if (id == null) {
+		if (version == null) {
 			beanWrapper.setProperty(versionProperty, 0);
 			doSave(collectionName, objectToSave, this.mongoConverter);
 		} else {
@@ -771,7 +772,7 @@ public class MongoTemplate implements MongoOperations, ApplicationContextAware {
 			assertUpdateableIdIfNotSet(objectToSave);
 
 			// Create query for entity with the id and old version
-			Object version = beanWrapper.getProperty(versionProperty);
+			Object id = beanWrapper.getProperty(idProperty);
 			Query query = new Query(Criteria.where(idProperty.getName()).is(id).and(versionProperty.getName()).is(version));
 
 			// Bump version number

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

@@ -1310,6 +1310,19 @@ public class MongoTemplateTests {
 		template.save(person);
 	}
 
+	/**
+	 * @see DATAMONGO-562
+	 */
+	@Test
+	public void optimisticLockingHandlingWithExistingId() {
+
+		PersonWithVersionPropertyOfTypeInteger person = new PersonWithVersionPropertyOfTypeInteger();
+		person.id = new ObjectId().toString();
+		person.age = 29;
+		person.firstName = "Patryk";
+		template.save(person);
+	}
+
 	/**
 	 * @see DATAMONGO-539
 	 */