Maven internal state should not allow to become "broken"

It seems by certain goal combinations we can make Maven Project instance state end up in "wrong" state. Example:

• create a packaging=pom project
• invoke jar:jar deploy:deploy

This will result in following:

• MavenProject has packaging=pom
• but, jar:jar will create (an empty) JAR and make it "main artifact" basically making JAR as main artifact with ".pom" extension (following what packaging artifact handler tells)
• deploy will happily deploy the jar as pom (as it is the only one artifact in project, but backing file is empty JAR, no "replacement" happens here)

Multiple issues here:

• Maven should "protect" MavenProject instance IMHO
• jar:jar should not (or core should not allow) to "break the state"
• m-deploy-p should figure out this situation: we deal with two artifacts (POM and "main JAR") but due packaging they end up on same URL?