
Attach (recommended) or Link to PDF file here:
[NAPEN16171380959.pdf](https://github.com/mozilla/pdf.js/files/6143802/NAPEN16171380959.pdf)

Configuration:
- Web browser and its version: Firefox 88 Nightly
- Operating system and its version: Windows 10
- PDF.js version:
- Is a browser extension: No

What went wrong? (add screenshot)
![](https://user-media-prod-cdn.itsre-sumo.mozilla.net/uploads/images/2021-03-15-10-58-27-ce2796.png)


var glyphsIds = "";
    var bias = 0;
    var range, start, end, codes;
    for (i = 0, ii = bmpLength; i < ii; i++) {
      range = ranges[i];
      start = range[0];
      end = range[1];
      startCount += string16(start);
      endCount += string16(end);
      codes = range[2];
      var contiguous = true;
      for (j = 1, jj = codes.length; j < jj; ++j) {
        if (codes[j] !== codes[j - 1] + 1) {
          contiguous = false;
          break;
        }
      }
      if (!contiguous) {
        var offset = (segCount - i) * 2 + bias * 2;
        bias += end - start + 1;
        idDeltas += string16(0);
        idRangeOffsets += string16(offset);
        for (j = 0, jj = codes.length; j < jj; ++j) {
          glyphsIds += string16(codes[j]);
        }
      } else {
        var startCode = codes[0];
        idDeltas += string16((startCode - start) & 0xffff);
        idRangeOffsets += string16(0);
      }