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 )

this.ctx.canvas.width,
      combinedScale[0]
    );
    const dimy = this.getSizeAndScale(
      ystep,
      this.ctx.canvas.height,
      combinedScale[1]
    );
    const tmpCanvas = owner.cachedCanvases.getCanvas(
      "pattern",
      dimx.size,
      dimy.size,
      true
    );
    const tmpCtx = tmpCanvas.context;
    const graphics = canvasGraphicsFactory.createCanvasGraphics(tmpCtx);
    graphics.groupLevel = owner.groupLevel;
    this.setFillAndStrokeStyleToContext(graphics, paintType, color);
    graphics.transform(dimx.scale, 0, 0, dimy.scale, 0, 0);
    this.clipBbox(graphics, bbox, x0, y0, x1, y1);
    graphics.baseTransform = graphics.ctx.mozCurrentTransform.slice();
    graphics.executeOperatorList(operatorList);
    graphics.endDrawing();
    return {
      canvas: tmpCanvas.canvas,
      scaleX: dimx.scale,
      scaleY: dimy.scale,
    };
  }
  getSizeAndScale(step, realOutputSize, scale) {