Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version: Chrome 90.0.4430.93
- Operating system and its version: macOs Big Sur 11.2.3
- PDF.js version: 2.7.570
- Is a browser extension: No

Steps to reproduce the problem:
1. Load the attached pdf in https://mozilla.github.io/pdf.js/web/viewer.html
2. Go to page 46. Dotted lines are missing in the graphics (see screenshot from acrobat reader)

What is the expected behavior? (add screenshot) See the screenshot
[Technical_Guide_UK.pdf](https://github.com/mozilla/pdf.js/files/6413001/Technical_Guide_UK.pdf)
![Screenshot 2021-05-03 at 07 46 09](https://user-images.githubusercontent.com/3785784/116844541-a343fd80-abe3-11eb-94c3-d03b3dfd6769.png)

p1 = [coordsArr[2], coordsArr[3]];
        r0 = null;
        r1 = null;
        type = "axial";
      } else if (shadingType === ShadingType.RADIAL) {
        p0 = [coordsArr[0], coordsArr[1]];
        p1 = [coordsArr[3], coordsArr[4]];
        r0 = coordsArr[2];
        r1 = coordsArr[5];
        type = "radial";
      } else {
        unreachable(`getPattern type unknown: ${shadingType}`);
      }
      const matrix = this.matrix;
      if (matrix) {
        p0 = Util.applyTransform(p0, matrix);
        p1 = Util.applyTransform(p1, matrix);
        if (shadingType === ShadingType.RADIAL) {
          const scale = Util.singularValueDecompose2dScale(matrix);
          r0 *= scale[0];
          r1 *= scale[1];
        }
      }
      return ["RadialAxial", type, this.bbox, this.colorStops, p0, p1, r0, r1];
    },
  };
  return RadialAxial;
})();
Shadings.Mesh = (function MeshClosure() {
  function MeshStreamReader(stream, context) {