Attach (recommended) or Link to PDF file here:
[PATTYP2.pdf](https://github.com/mozilla/pdf.js/files/6471935/PATTYP2.pdf)

Configuration:
- Web browser and its version: FF 88.0.1
- Operating system and its version: W10.0.19042.985
- PDF.js version: https://mozilla.github.io/pdf.js/web/viewer.html

Steps to reproduce the problem:
1. open file to display

What is the expected behavior? (add screenshot)
![grafik](https://user-images.githubusercontent.com/6665575/118114800-5e407800-b3e8-11eb-860f-019f48a8eabf.png)

What went wrong? (add screenshot)
![grafik](https://user-images.githubusercontent.com/6665575/118114841-6c8e9400-b3e8-11eb-8252-1517e5d76475.png)

(memo for me: when fixed, check the files in https://issues.apache.org/jira/browse/PDFBOX-1958 )

ctx.save();
        ctx.transform(
          scaleX,
          skewX,
          skewY,
          scaleY,
          positions[i],
          positions[i + 1]
        );
        ctx.scale(1, -1);
        ctx.drawImage(maskCanvas.canvas, 0, 0, width, height, 0, -1, 1, 1);
        ctx.restore();
      }
    }
    paintImageMaskXObjectGroup(images) {
      if (!this.contentVisible) {
        return;
      }
      const ctx = this.ctx;
      const fillColor = this.current.fillColor;
      const isPatternFill = this.current.patternFill;
      for (let i = 0, ii = images.length; i < ii; i++) {
        const image = images[i];
        const width = image.width,
          height = image.height;
        const maskCanvas = this.cachedCanvases.getCanvas(
          "maskCanvas",
          width,
          height
        );