Looks like very similar issue is now present in 4.3.0.
With the same scenario I get this:

java.lang.NullPointerException
at org.hibernate.jpa.criteria.path.AbstractPathImpl.getPathIdentifier(AbstractPathImpl.java:92)
at org.hibernate.jpa.criteria.path.AbstractPathImpl.render(AbstractPathImpl.java:252)
at org.hibernate.jpa.criteria.predicate.ComparisonPredicate.render(ComparisonPredicate.java:187)
at org.hibernate.jpa.criteria.predicate.AbstractSimplePredicate.render(AbstractSimplePredicate.java:65)
at org.hibernate.jpa.criteria.QueryStructure.render(QueryStructure.java:262)
at org.hibernate.jpa.criteria.CriteriaQueryImpl.interpret(CriteriaQueryImpl.java:312)
at org.hibernate.jpa.criteria.compile.CriteriaCompiler.compile(CriteriaCompiler.java:147)
at org.hibernate.jpa.spi.AbstractEntityManagerImpl.createQuery(AbstractEntityManagerImpl.java:736)

Reverting back to 4.1.6 gets rid of this exception.
So, this is either a regression or a new issue with the same nasty effect as