Functional test: atomicSet updates to embedded documents do not work

[blockjon]

Making a change to the embedded document in this test fails to update the MongoDB record.

This test passes if strategy="set" is used.

repro:

phpunit --filter testFailureToUpdateEmbeddedDocumentWithAtomicSet

emits:

PHPUnit 4.1.6-9-gbe3530d by Sebastian Bergmann.

Configuration read from /mongodb-odm/phpunit.xml

F

Time: 1.41 seconds, Memory: 21.75Mb

There was 1 failure:

1) Doctrine\ODM\MongoDB\Tests\Functional\Ticket\GHXXXXTest::testFailureToUpdateEmbeddedDocumentWithAtomicSet
The chapter title failed to update.
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-'First chapter A'
+'A'

/mongodb-odm/tests/Doctrine/ODM/MongoDB/Tests/Functional/Ticket/GHXXXXTest.php:33

FAILURES!
Tests: 1, Assertions: 1, Failures: 1.

[malarzm]