Problem fixed in Grails 2.3.2.BUILD-SNAPSHOT

Your test passes with these changes. Problems in "raw" codec were fixed recently while fixing http://jira.grails.org/browse/GRAILS-10641.

You can get Grails 2.3.2.BUILD-SNAPSHOT version from http://hudson.grails.org/job/grails_core_2.3.x/lastSuccessfulBuild/artifact/build/distributions/grails-2.3.2.BUILD-
SNAPSHOT.zip