When publishing content through the eZ Publish api (both legacy and the new public API), the level attribute on header elements is set to "0" when the content is first edited through the back-office, and then "1" after saving the content once more.

Steps to reproduce:

• Through the legacy or new public API, create a new Article object, and set its intro or body to:

<?xml version="1.0" encoding="utf-8"?>
<section xmlns:image="http://ez.no/namespaces/ezpublish3/image/"
  xmlns:xhtml="http://ez.no/namespaces/ezpublish3/xhtml/"
  xmlns:custom="http://ez.no/namespaces/ezpublish3/custom/">
    <header level="3">Level 3 Heading</header>
</section>

• Through the administration interface, edit the newly published object, and verify that the level attribute is not preserved correctly.