title: The output parameter 'CopiedFiles' of Copy task is returning all the files specified to copy even if it copies nothing given SkipUnchangedFiles="true"
body: <p>The CopiedFiles parameter is returning all the files that were intended to be copied. But given the fact that SkipUnchangedFiles is set to true and ttask itself is not copying anything as can be seen on command line (no copying message). Why not, then, CopiedFiles is empty?</p>
  
  <p>I need to have CopiedFiles parameter be populated only with files that were actually copied (because they were changed) in order to further copy these files into some other folder. This is to maintain an up-to-date release folder as well as to extract only those files which actually need to be propogated onto UAT/production server.</p>
  
  <p>For reference sake, the copy task code I'm using is given below:</p>
  
  <pre>
  &lt;Copy SkipUnchangedFiles="true"
              SourceFiles="@(cfile)"
                  DestinationFiles="@(cfile->'$(PublishDir)\%(Identity)')"&gt;
  
          &lt;Output
                      TaskParameter="CopiedFiles"
                      ItemName="Changed" /&gt;
  
  &lt;/Copy&gt;
  
  &lt;Message Text="changed:@(Changed)" Importance="high" /&gt;
  
  </pre>
  
  <p>Is there a bug in the copy task or this is the intended behavior.</p>