title: setDefaultReturnToken messes up syntax highlighting
body: <p>I'm developing an eclipse plugin with a custom text editor for which I want to provide syntax highlighting. Therefore I have implemented my own <code>RuleBasedPartitionScanner</code> and a respective <code>SourceViewerConfiguration</code>.<br>
  Everything is working fine when I don't mess with the defaultReturnToken of the PartitionScanner but when I try to set the default defaultReturnToken the syntax highlighting disappears.  </p>
  
  <p>My PartitionScanner:  </p>
  
  <pre><code>public class SQFPartitionScanner extends RuleBasedPartitionScanner {
  
      public static final String SQF_COMMENT = "__sqf_Comment";
      public static final String SQF_CODE = "__sqf_Code";
  
      public SQFPartitionScanner() {
          IToken comment = new Token(SQF_COMMENT);
          IToken code = new Token(SQF_CODE);
  
          IPredicateRule[] rules = {
                  //rule for multiLine comments
                  new MultiLineRule("/*", "*/", comment),
                  //rule for singleLine comments
                  new EndOfLineRule("//", comment)
          };
  
          this.setPredicateRules(rules);
  
          this.setDefaultReturnToken(code);
      }
  
  }
  </code></pre>
  
  <p>As the produced token of this no longer of type <code>IDocument.DEFAULT_CONTENT_TYPE</code> but instead of type <code>SQFPartitioScanner.CODE</code> I changed my <code>SourceViewerConfiguration</code> as followed (I only changed the <code>getPresentationReconciler()</code>-method):  </p>
  
  <pre><code>public IPresentationReconciler getPresentationReconciler(ISourceViewer sourceViewer) {
          PresentationReconciler reconciler = new PresentationReconciler();
  
          DefaultDamagerRepairer dr = new DefaultDamagerRepairer(this.getKeywordScanner());
  //      reconciler.setDamager(dr, IDocument.DEFAULT_CONTENT_TYPE);
  //      reconciler.setRepairer(dr, IDocument.DEFAULT_CONTENT_TYPE);
          reconciler.setDamager(dr, SQFPartitionScanner.SQF_CODE);
          reconciler.setRepairer(dr, SQFPartitionScanner.SQF_CODE);
  
          return reconciler;
      }
  </code></pre>
  
  <p>Is there something else I have to change for the syntax highlighting to work with the defaultReturnToken set to <code>SQFPartitionScanner.SQF_CODE</code>?  </p>
  
  <p><strong>EDIT:</strong><br>
  When I uncomment the lines  </p>
  
  <pre><code>//      reconciler.setDamager(dr, IDocument.DEFAULT_CONTENT_TYPE);
  //      reconciler.setRepairer(dr, IDocument.DEFAULT_CONTENT_TYPE);
  </code></pre>
  
  <p>and comment  </p>
  
  <pre><code>reconciler.setDamager(dr, SQFPartitionScanner.SQF_CODE);
  reconciler.setRepairer(dr, SQFPartitionScanner.SQF_CODE);
  </code></pre>
  
  <p>I still get no syntax highlighting.<br>
  Because of that I suspect that the default token is not properly created because obviously it's not of type <code>IDocument.DEFAULT_CONTENT_TYPE</code> anymore but it's not of type <code>SQFPartitionScanner.SQF_CODE</code> neither</p>