Incorrect cascade on delete

Details

Type: Bug
Status: Closed
Priority: Critical
Resolution: Fixed
Affects Version/s: None
Fix Version/s: 0.6
Component/s: None
Labels:
None
Environment:
Revision 5339

Description

When I have a domain class that uses 'static belongsTo = [ prop: relClass ]', deleting an instance of that class causes the related instance to be deleted on PostgreSQL. If any other instances link to the same related instance, that delete will fail, throwing an exception.

Take the following domain classes for example:

class Role {
    String name
}

class UserRoleRel {
    String username

    static belongsTo = [ role: Role ]
}

Deleting an instance of UserRoleRel will also delete the associated Role instance. The problem appears to stem from GrailsDomainBinder - in particular the bindProperty() method:

    public static void bindProperty(...) {
        ...
            // in a one-to-one we check if it is un-directional and the other side is an owning side and then cascade
            // otherwise if is the ownside we cascade all
            else if(grailsProperty.isOneToOne()) {
                GrailsDomainClass domainClass = grailsProperty.getDomainClass();
                if(!grailsProperty.isBidirectional() && domainClass.isOwningClass(grailsProperty.getType())) {
                    // THIS IS CALLED!
                    prop.setCascade(CASCADE_ALL);
                }
                else if(grailsProperty.isOwningSide()) {
                    prop.setCascade(CASCADE_ALL);
                }
            }
        ...
    }

The line after "// THIS IS CALLED!" is invoked for the 'role' property, setting up a cascading delete, even though it is not the owning side of the relationship.

I have attached a simple example that exhibits the problem.