Trying to read a pdf file using PDFJS.getDocument function. The pdf worker is throwing


UnknownErrorException {
 name: "UnknownErrorException", 
 message: "Invalid root reference", 
 details: "FormatError: Invalid root reference"
}

The error can be easily reproduced calling PDFJS.getDocument(pdfUrl) using the attached pdf
[110229_10312017_6810306.pdf](https://github.com/mozilla/pdf.js/files/1444166/110229_10312017_6810306.pdf)


if (this._newRefNum === null) {
      this._newRefNum = this.entries.length || 1;
    }
    return Ref.get(this._newRefNum++, 0);
  }
  resetNewRef() {
    this._newRefNum = null;
  }
  setStartXRef(startXRef) {
    
    
    this.startXRefQueue = [startXRef];
  }
  parse(recoveryMode = false) {
    let trailerDict;
    if (!recoveryMode) {
      trailerDict = this.readXRef();
    } else {
      warn("Indexing all PDF objects");
      trailerDict = this.indexObjects();
    }
    trailerDict.assignXref(this);
    this.trailer = trailerDict;
    let encrypt;
    try {
      encrypt = trailerDict.get("Encrypt");
    } catch (ex) {