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)


throw new FormatError("Failed to read XRef stream");
          }
        } else {
          throw new FormatError("Invalid XRef stream header");
        }
        
        obj = dict.get("Prev");
        if (Number.isInteger(obj)) {
          this.startXRefQueue.push(obj);
        } else if (obj instanceof Ref) {
          
          
          this.startXRefQueue.push(obj.num);
        }
        this.startXRefQueue.shift();
      }
      return this.topDict;
    } catch (e) {
      if (e instanceof MissingDataException) {
        throw e;
      }
      info("(while reading XRef): " + e);
      this.startXRefQueue.shift();
    }
    if (recoveryMode) {
      return undefined;
    }
    throw new XRefParseException();
  }
  getEntry(i) {