Attach (recommended) or Link to PDF file here: [A3_Quer.pdf](https://github.com/mozilla/pdf.js/files/7373152/A3_Quer.pdf)


**Configuration:**

- Web browser and its version: Firefox 93.0
- Operating system and its version: macOS 11.6
- PDF.js version: 2.5.207
- Is a browser extension: no

**Steps to reproduce the problem:**
1. Open the attached file in Firefox

We discovered this issue in on older version of this library, but it can be reproduced in the current version of Firefox.

**What is the expected behavior? (add screenshot)**
The file should be rendered with a linear gradient as a background:
![Bildschirmfoto 2021-10-19 um 14 34 00](https://user-images.githubusercontent.com/8649002/137910027-07947e34-700b-4692-b225-d38c36da0d37.png)


**What went wrong? (add screenshot)**
The file is rendered without any background:
![Bildschirmfoto 2021-10-19 um 14 35 05](https://user-images.githubusercontent.com/8649002/137910215-a6b8fb9e-ff95-49f0-93b4-c9f127bd49c1.png)



**Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):**
none
const figureMaxX = Math.max(
      coords[pi[0]][0],
      coords[pi[3]][0],
      coords[pi[12]][0],
      coords[pi[15]][0]
    );
    const figureMaxY = Math.max(
      coords[pi[0]][1],
      coords[pi[3]][1],
      coords[pi[12]][1],
      coords[pi[15]][1]
    );
    let splitXBy = Math.ceil(
      ((figureMaxX - figureMinX) * MeshShading.TRIANGLE_DENSITY) /
        (this.bounds[2] - this.bounds[0])
    );
    splitXBy = Math.max(
      MeshShading.MIN_SPLIT_PATCH_CHUNKS_AMOUNT,
      Math.min(MeshShading.MAX_SPLIT_PATCH_CHUNKS_AMOUNT, splitXBy)
    );
    let splitYBy = Math.ceil(
      ((figureMaxY - figureMinY) * MeshShading.TRIANGLE_DENSITY) /
        (this.bounds[3] - this.bounds[1])
    );
    splitYBy = Math.max(
      MeshShading.MIN_SPLIT_PATCH_CHUNKS_AMOUNT,
      Math.min(MeshShading.MAX_SPLIT_PATCH_CHUNKS_AMOUNT, splitYBy)
    );
    const verticesPerRow = splitXBy + 1;
    const figureCoords = new Int32Array((splitYBy + 1) * verticesPerRow);