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 )

const activeSMask = this.current.activeSMask;
      const drawnWidth = activeSMask.canvas.width;
      const drawnHeight = activeSMask.canvas.height;
      const cacheId = "smaskGroupAt" + this.groupLevel;
      const scratchCanvas = this.cachedCanvases.getCanvas(
        cacheId,
        drawnWidth,
        drawnHeight,
        true
      );
      const currentCtx = this.ctx;
      const currentTransform = currentCtx.mozCurrentTransform;
      this.ctx.save();
      const groupCtx = scratchCanvas.context;
      groupCtx.scale(1 / activeSMask.scaleX, 1 / activeSMask.scaleY);
      groupCtx.translate(-activeSMask.offsetX, -activeSMask.offsetY);
      groupCtx.transform.apply(groupCtx, currentTransform);
      activeSMask.startTransformInverse = groupCtx.mozCurrentTransformInverse;
      copyCtxState(currentCtx, groupCtx);
      this.ctx = groupCtx;
      this.setGState([
        ["BM", "source-over"],
        ["ca", 1],
        ["CA", 1],
      ]);
      this.groupStack.push(currentCtx);
      this.groupLevel++;
    }
    suspendSMaskGroup() {