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)


xref: this,
        allowStreams: true,
      });
      const obj = parser.getObj();
      entries[i] = obj;
      if (obj instanceof BaseStream) {
        continue;
      }
      const num = nums[i],
        entry = this.entries[num];
      if (entry && entry.offset === tableOffset && entry.gen === i) {
        if (
          typeof PDFJSDev === "undefined" ||
          PDFJSDev.test("!PRODUCTION || TESTING")
        ) {
          assert(
            obj !== undefined,
            'fetchCompressed: The "obj" cannot be undefined.'
          );
        }
        this._cacheMap.set(num, obj);
      }
    }
    xrefEntry = entries[xrefEntry.gen];
    if (xrefEntry === undefined) {
      throw new XRefEntryException(`Bad (compressed) XRef entry: ${ref}`);
    }
    return xrefEntry;
  }
  async fetchIfRefAsync(obj, suppressEncryption) {