doctrine/phpcr-odm — pull request #192 by lsmith77 (2012-11-23 21:09:38+00:00)
Title: use plain php arrays for multivalue properties (major BC breaks!)

using MultivaluePropertyCollection complicated usage, since it was
impossile to map plain PHP arrays since code could not rely on them
coming back as plain PHP arrays.

it turns out however that MultivaluePropertyCollection is also slower
than using simple comparisons to determine if data has changed.

see https://t.co/9LL3wU9w for details

so this commit replaces MultivaluePropertyCollection support by using
plain php arrays for multivalue properties. for ReferenceMany we still
benefit from the lazy loading, so this remains unchanged.

furthermore this commit also ensures that a missing node property is
interpreted as an empty array when creating a document from data stored
in PHPCR, which is another BC break.