Pitfall with grails projections

With grails projections one should keep in mind that when one of the associated values turns out to be null, the entire entry is ignored in the result list. I found numerous posts, where this problem is addressed by alternating the join mode from inner join to left outer join:

http://www.intelligrape.com/blog/2011/11/01/criteria-query-with-left-outer-join/
http://stackoverflow.com/questions/17083204/criteria-uses-inner-join-instead-left-join-approach-by-default-making-my-que
http://stackoverflow.com/questions/19390720/grails-2-x-createcriteria-or-doesnt-work-for-nested-associations/19391255#19391255

Now, I do something like this: