Created attachment 855125 [details]
kjar containing process with human task

Description of problem:

the rest API call /task/{taskId}/content returns null content


Version-Release number of selected component (if applicable):
BPMS 6.0.0.CR1


How reproducible:
Consistently


Steps to Reproduce:
1. make sure the user has role 'Reviewer'
2. Log in into BPMS
3. Deploy the attached kjar (contains a very simple process with a human task)
4. In the BPMS UI, start an instance of the UserTask process - this will create a new task. Verify the taskId in the task tab.
5. In a command window, issue the following command:

curl -HAccept:application/xml --user "<user>:<password>" "localhost:8080/business-central/rest/task/<taskId>/content"

(Replace <user> and <password> with the actual username and password, and <taskId> with the actual task id)

Actual results: nothing is returned from the call


Expected results: task content in xml format


Additional info: 

in org.kie.services.remote.rest.TaskResource, lines 272 - 280

        JaxbContent content = null;
        if( contentId > -1 ) { 
            cmd = new GetContentCommand(contentId);
            result = processRequestBean.doTaskOperationAndSerializeResult(
                    cmd, 
                    "Unable get content " + contentId + " (from task " + taskId + ")");
            content = (JaxbContent) content;
        } 
        return createCorrectVariant(content, headers);

line 278 should become

content = (JaxbContent) result;

instead of

content = (JaxbContent) content;