Attach (recommended) or Link to PDF file here:
[Scan-to-Mail-PDF1_(1).pdf](https://github.com/mozilla/pdf.js/files/6876708/Scan-to-Mail-PDF1_.1.pdf)

Configuration:
- Web browser and its version: Firefox Developer 91.0b7 (64-Bit)
- Operating system and its version: Windows 10 (21H1)
- PDF.js version: 2.10.339 (also tested with the online demo, Version 2.11.5)
- Is a browser extension:

Steps to reproduce the problem:
1. Open the attached pdf
2. Scroll to page 3

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/7944797/126957487-cc7a2d19-adfb-42e4-9809-74e1a7a85048.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/7944797/126957351-29aebb4d-eadd-4273-b69d-530b9060c12c.png)




xNew =
          affectedBoundary.index > boundary.index
            ? affectedBoundary.x1New
            : boundary.x1;
      } else if (affectedBoundary.x2New === undefined) {
        
        
        xNew = (affectedBoundary.x2 + boundary.x1) / 2;
      } else {
        
        xNew = affectedBoundary.x2New;
      }
      if (xNew > maxXNew) {
        maxXNew = xNew;
      }
    }
    
    boundary.x1New = maxXNew;
    
    for (q = i; q <= j; q++) {
      horizonPart = horizon[q];
      affectedBoundary = horizonPart.boundary;
      if (affectedBoundary.x2New === undefined) {
        
        if (affectedBoundary.x2 > boundary.x1) {
          
          
          if (affectedBoundary.index > boundary.index) {
            affectedBoundary.x2New = affectedBoundary.x2;
          }