title: Grails many-to-many associations and preventing cascade
body: <p>So, we have a many-to-many relationship between Customer and Role, set up as:</p>
  
  <pre><code>Customer {
    static hasMany = [roles: Role]
  }
  
  Role {
    static hasMany = [customer: Customer]
    static belongsTo = Customer
  }
  </code></pre>
  
  <p>The Role object has only a name and a set of permissions. We don't want to cascade saves from Customer -> Role, as Role should only get modified directly.</p>
  
  <p>I added:</p>
  
  <pre><code>static mapping = {
    roles cascade: 'none'
  }
  </code></pre>
  
  <p>but, whenever, I create a customer, the role table gets updated as well. Nothing changes, except that the version number is incremented.</p>
  
  <p>Am I missing something else that needs to be set ... is there a bug with how many-to-many relationships and cascades are set in Grails ... or is there some other way I can prevent roles from being updated every time?</p>