Attach (recommended) or Link to PDF file here:
[PATTYP2.pdf](https://github.com/mozilla/pdf.js/files/6471935/PATTYP2.pdf)

Configuration:
- Web browser and its version: FF 88.0.1
- Operating system and its version: W10.0.19042.985
- PDF.js version: https://mozilla.github.io/pdf.js/web/viewer.html

Steps to reproduce the problem:
1. open file to display

What is the expected behavior? (add screenshot)
![grafik](https://user-images.githubusercontent.com/6665575/118114800-5e407800-b3e8-11eb-860f-019f48a8eabf.png)

What went wrong? (add screenshot)
![grafik](https://user-images.githubusercontent.com/6665575/118114841-6c8e9400-b3e8-11eb-8252-1517e5d76475.png)

(memo for me: when fixed, check the files in https://issues.apache.org/jira/browse/PDFBOX-1958 )

}
  if (data[pos] !== 0) {
    points[j0 + j] = 4;
    ++count;
  }
  if (count > POINT_TO_PROCESS_LIMIT) {
    return null;
  }
  
  const steps = new Int32Array([0, width1, -1, 0, -width1, 0, 0, 0, 1]);
  const outlines = [];
  for (i = 0; count && i <= height; i++) {
    let p = i * width1;
    const end = p + width;
    while (p < end && !points[p]) {
      p++;
    }
    if (p === end) {
      continue;
    }
    const coords = [p % width1, i];
    const p0 = p;
    let type = points[p];
    do {
      const step = steps[type];
      do {
        p += step;
      } while (!points[p]);
      const pp = points[p];
      if (pp !== 5 && pp !== 10) {