PermissionTarget fails when updating group-based targets

[matt-rean]

Version:

2.8.2

Environment:

RHEL7

Scenario:

When attempting to update an existing permissions target with no user in the principal, the gem fails with an exception. I believe it's failing because the user portion of the principal is nil and abbreviate_principal is expecting it. This could cause a variety of issues since principal is not a required field in the PermissionTarget api, but the gem always uses it.

Steps to Reproduce:

Create a permission target with permissions assigned only by group, with no users. Attempt to update the repository list on the permissions target.

Expected Result:

The permissions target should update with the configuration parameters passed in to the request.

Actual Result:

NoMethodError: undefined method map' for nil:NilClass /home/ec2-user/.rvm/gems/ruby-2.4.2/gems/artifactory-2.8.2/lib/artifactory/resources/permission_target.rb:116:in abbreviate_principal'
/home/ec2-user/.rvm/gems/ruby-2.4.2/gems/artifactory-2.8.2/lib/artifactory/resources/permission_target.rb:96:in to_abbreviated' /home/ec2-user/.rvm/gems/ruby-2.4.2/gems/artifactory-2.8.2/lib/artifactory/resources/permission_target.rb:151:in save'
/opt/scratch/src/platform-bootstrap-omnibus/rakelib/bug.rake:10:in block (2 levels) in <top (required)>' /home/ec2-user/.rvm/gems/ruby-2.4.2/bin/ruby_executable_hooks:15:in eval'
/home/ec2-user/.rvm/gems/ruby-2.4.2/bin/ruby_executable_hooks:15:in `

'

Thank you!