title: Jenkins does not update build result to better result
body: <p>I have a groovy script that changes the build result using setResult(hudson.model.Result.SUCCESS).</p>
  
  <p>But I realized that I cannot change the job result to a better result (only to worse ones). If I will change the code to: build.setResult(hudson.model.Result.Unstable), then when the build will be successful the result will be changed (I can see in the Console Output: Build step 'Groovy Postbuild' changed build result to UNSTABLE.)
  But I can't update the result to a better one.</p>
  
  <p>Is there any solution?
  (The same problem occurs with groovy postbuild) .</p>
  
  <p>EDIT:
  I'm using the MultiJob plugin in my main job for running 3 downstream jobs (named job1, job2, job3). And I wrote a groovy script so that the result of the main job will be determine only by the first two downstream jobs (when job1 and job2 are success, and job3 is unstable - I wish to set the main job result to success).
  because of the problem mentioned above I can't do it... any ideas?</p>
  
  <p>Thanks.</p>