Attach (recommended) or Link to PDF file here:
See pdf in https://github.com/mozilla/pdf.js/issues/3109

Configuration:
- Web browser and its version: Firefox nightly
- Operating system and its version: Windows 10
- PDF.js version: builtin viewer

Steps to reproduce the problem:
1. Look at outlines

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/141514798-0e656865-1cbf-4fb8-a89b-530d36da23c9.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/141514740-c95e0237-8bf4-4129-a4a5-cb2ea5a3f4df.png)

function compare(a, b) {
      return a - b;
    }
    
    const orderedX = [rect1[0], rect1[2], rect2[0], rect2[2]].sort(compare);
    const orderedY = [rect1[1], rect1[3], rect2[1], rect2[3]].sort(compare);
    const result = [];
    rect1 = Util.normalizeRect(rect1);
    rect2 = Util.normalizeRect(rect2);
    
    if (
      (orderedX[0] === rect1[0] && orderedX[1] === rect2[0]) ||
      (orderedX[0] === rect2[0] && orderedX[1] === rect1[0])
    ) {
      
      result[0] = orderedX[1];
      result[2] = orderedX[2];
    } else {
      return null;
    }
    
    if (
      (orderedY[0] === rect1[1] && orderedY[1] === rect2[1]) ||
      (orderedY[0] === rect2[1] && orderedY[1] === rect1[1])