archiveClasses and attachClasses in 2.1

There seems to be a regression between 2.1-beta-1 and 2.1 with regard to archiveClasses and attachClasses options.

My use case:
I have a WAR project with Java classes and I am setting both archiveClasses and attachClasses to true.
With 2.1-beta-1 it was working correctly (mvn clean install) --> I got classes packaged into a JAR and placed into WEB-INF/lib and I got that JAR artifact deployed to my Maven repository.

Just upgraded to 2.1 and I got the following with the same use case: I got classes packaged into a JAR and placed into WEB-INF/lib (correct) and I got an empty JAR artifact (only META-INF/ present) deployed to my Maven repository (incorrect).

Looking at the code in 2.1 of WarMojo (line 230) I am seeing that the classes folder (for classes to be included into attached artifact) is empty, because it was cleared before due to archiveClasses=true

Trying to debug both code branches I am seeing a difference between 2.1-beta-1 and 2.1 in that the
getJarArchiver().getDirs() before the call to packager.packageClasses() method (line 233/234)

is empty in the 2.1:
(java.util.HashMap<K,V>) {}

whereas it is not in 2.1-beta-1. It contains a list of all my classes, perhaps because the same archiver instance was used to package them into JAR for WEB-INF/lib.
That is why I am getting all my classes in the attached artifact with 2.1-beta-1

I would really need your help in understanding the "correct" behaviour.
Is this a regression bug for 2.1 or I am completely wrong in my expectations about archiveClasses and attachClasses used together?

Kind regards
Sergiy Shyrkov