Attach (recommended) or Link to PDF file here: https://d15k2d11r6t6rl.cloudfront.net/public/users/Integrators/a0a42ab5-3cb9-4912-84b7-3c6e47330d5c/smart-pr-805/Consumentenfolder_A5_zonder_paskruizen%20_2.pdf (and the similar other files under "Informatiefolder" on https://news.pressmailings.com/hvdm/partnertoolkit)

Configuration:
- Web browser and its version: Firefox 84.0 (64 bits)
- Operating system and its version: Arch Linux
- PDF.js version: 2.7.262 (built-in) and 2.7.434 (development version at time of writing)
- Is a browser extension: no

Steps to reproduce the problem:
1. Open the linked PDF file linked above.
2. Notice that the first page is rendered completely broken. There are no warnings/errors in the console unfortunately, and it's not related to layers since the document does not contain any.

What is the expected behavior? (add screenshot)
![good](https://user-images.githubusercontent.com/1993262/103363234-e158d580-4aba-11eb-9eb7-fe0db9f0a193.png)

What went wrong? (add screenshot)
![broken](https://user-images.githubusercontent.com/1993262/103363239-e4ec5c80-4aba-11eb-9f7d-3edac62ece3c.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension): -
const drawnWidth = Math.ceil(rect[2] - rect[0]);
    const drawnHeight = Math.ceil(rect[3] - rect[1]);
    const fillCanvas = this.cachedCanvases.getCanvas(
      "fillCanvas",
      drawnWidth,
      drawnHeight,
      true
    );
    const fillCtx = fillCanvas.context;
    
    const offsetX = Math.min(cord1[0], cord2[0]);
    const offsetY = Math.min(cord1[1], cord2[1]);
    fillCtx.translate(-offsetX, -offsetY);
    fillCtx.transform.apply(fillCtx, maskToCanvas);
    
    const scaled = this._scaleImage(
      maskCanvas.canvas,
      fillCtx.mozCurrentTransformInverse
    );
    fillCtx.imageSmoothingEnabled = getImageSmoothingEnabled(
      fillCtx.mozCurrentTransform,
      img.interpolate
    );
    fillCtx.drawImage(
      scaled.img,
      0,
      0,
      scaled.img.width,
      scaled.img.height,
      0,