DATAMONGO-571 - Fixed setting null values during update of versioned entities.

In case of updating a versioned object,the Update object is now constructed from plain key value pairs, not using $set anymore. This will correctly set the null values in the updated document.

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2012 the original author or authors.
+ * Copyright 2010-2013 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -52,7 +52,10 @@ public class Update {
 
 	/**
 	 * Creates an {@link Update} instance from the given {@link DBObject}. Allows to explicitly exlude fields from making
-	 * it into the created {@link Update} object.
+	 * it into the created {@link Update} object. Note, that this will set attributes directly and <em>not</em> use
+	 * {@literal $set}. This means fields not given in the {@link DBObject} will be nulled when executing the update. To
+	 * create an only-updating {@link Update} instance of a {@link DBObject}, call {@link #set(String, Object)} for each
+	 * value in it.
 	 * 
 	 * @param object the source {@link DBObject} to create the update from.
 	 * @param exclude the fields to exclude.
@@ -69,7 +72,7 @@ public class Update {
 				continue;
 			}
 
-			update.set(key, object.get(key));
+			update.modifierOps.put(key, object.get(key));
 		}
 
 		return update;
@@ -160,7 +163,7 @@ public class Update {
 	 * @return
 	 */
 	public Update pop(String key, Position pos) {
-		addMultiFieldOperation("$pop", key, (pos == Position.FIRST ? -1 : 1));
+		addMultiFieldOperation("$pop", key, pos == Position.FIRST ? -1 : 1);
 		return this;
 	}
 

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

@@ -47,6 +47,7 @@ import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.dao.OptimisticLockingFailureException;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.annotation.PersistenceConstructor;
+import org.springframework.data.annotation.Version;
 import org.springframework.data.mapping.model.MappingException;
 import org.springframework.data.mongodb.InvalidMongoDbApiUsageException;
 import org.springframework.data.mongodb.MongoDbFactory;
@@ -1533,6 +1534,42 @@ public class MongoTemplateTests {
 		assertThat(template.count(query, collectionName), is(1L));
 	}
 
+	/**
+	 * @see DATAMONGO-571
+	 */
+	@Test
+	public void nullsPropertiesForVersionObjectUpdates() {
+
+		VersionedPerson person = new VersionedPerson();
+		person.firstname = "Dave";
+		person.lastname = "Matthews";
+
+		template.save(person);
+		assertThat(person.id, is(notNullValue()));
+
+		person.lastname = null;
+		template.save(person);
+
+		person = template.findOne(query(where("id").is(person.id)), VersionedPerson.class);
+		assertThat(person.lastname, is(nullValue()));
+	}
+
+	/**
+	 * @see DATAMONGO-571
+	 */
+	@Test
+	public void nullsValuesForUpdatesOfUnversionedEntity() {
+
+		Person person = new Person("Dave");
+		template.save(person);
+
+		person.setFirstName(null);
+		template.save(person);
+
+		person = template.findOne(query(where("id").is(person.getId())), Person.class);
+		assertThat(person.getFirstName(), is(nullValue()));
+	}
+
 	static class MyId {
 
 		String first;
@@ -1602,4 +1639,11 @@ public class MongoTemplateTests {
 		String state;
 		String city;
 	}
+
+	static class VersionedPerson {
+
+		@Version
+		Long version;
+		String id, firstname, lastname;
+	}
 }