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)


dict = this.processXRefTable(parser);
          if (!this.topDict) {
            this.topDict = dict;
          }
          
          obj = dict.get("XRefStm");
          if (Number.isInteger(obj)) {
            const pos = obj;
            
            
            if (!(pos in this.xrefstms)) {
              this.xrefstms[pos] = 1;
              this.startXRefQueue.push(pos);
            }
          }
        } else if (Number.isInteger(obj)) {
          
          if (
            !Number.isInteger(parser.getObj()) ||
            !isCmd(parser.getObj(), "obj") ||
            !((obj = parser.getObj()) instanceof BaseStream)
          ) {
            throw new FormatError("Invalid XRef stream");
          }
          dict = this.processXRefStream(obj);
          if (!this.topDict) {
            this.topDict = dict;
          }
          if (!dict) {