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 )

if (this.current.resumeSMaskCtx) {
        this.resumeSMaskGroup();
      }
      
      
      if (
        this.current.activeSMask !== null &&
        (this.stateStack.length === 0 ||
          this.stateStack[this.stateStack.length - 1].activeSMask !==
            this.current.activeSMask)
      ) {
        this.endSMaskGroup();
      }
      if (this.stateStack.length !== 0) {
        this.current = this.stateStack.pop();
        this.ctx.restore();
        
        this.pendingClip = null;
        this._cachedGetSinglePixelWidth = null;
      } else {
        
        this.current.activeSMask = null;
      }
    }
    transform(a, b, c, d, e, f) {