Unable to start JBoss when the JBoss group name is different from the user name

Issue

When starting JBoss, the startup scripts check if the jboss group exists but the test is incorrect.
It works "by chance" most of the time because the jboss user and the jboss group usually have the same name, but fails when they are different.

if [ -z "`id -g $JBOSS_GROUP 2>/dev/null`" ]; then
   failure "${NAME} startup"
   echo -n -e "\nGroup $JBOSS_GROUP does not exist. Create group first."
   echo -n -e "\n"
   return 3
fi

Instead, it should perform something like this :

if [ "`id -gn $JBOSS_USER 2>/dev/null`" = $JBOSS_GROUP ]; then

This affect both domain and standalone startup scripts:
/etc/init.d/jbossas
/etc/init.d/jbossas-domain