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
(-4 * coords[ps[0]][1] -
          coords[ps[15]][1] +
          6 * (coords[ps[4]][1] + coords[ps[1]][1]) -
          2 * (coords[ps[12]][1] + coords[ps[3]][1]) +
          3 * (coords[ps[13]][1] + coords[ps[7]][1])) /
          9,
      ]);
      ps[6] = coords.length;
      coords.push([
        (-4 * coords[ps[3]][0] -
          coords[ps[12]][0] +
          6 * (coords[ps[2]][0] + coords[ps[7]][0]) -
          2 * (coords[ps[0]][0] + coords[ps[15]][0]) +
          3 * (coords[ps[4]][0] + coords[ps[14]][0])) /
          9,
        (-4 * coords[ps[3]][1] -
          coords[ps[12]][1] +
          6 * (coords[ps[2]][1] + coords[ps[7]][1]) -
          2 * (coords[ps[0]][1] + coords[ps[15]][1]) +
          3 * (coords[ps[4]][1] + coords[ps[14]][1])) /
          9,
      ]);
      ps[9] = coords.length;
      coords.push([
        (-4 * coords[ps[12]][0] -
          coords[ps[3]][0] +
          6 * (coords[ps[8]][0] + coords[ps[13]][0]) -
          2 * (coords[ps[0]][0] + coords[ps[15]][0]) +
          3 * (coords[ps[11]][0] + coords[ps[1]][0])) /
          9,