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.fillText(character, x, y);
        }
        if (
          fillStrokeMode === TextRenderingMode.STROKE ||
          fillStrokeMode === TextRenderingMode.FILL_STROKE
        ) {
          if (resetLineWidthToOne) {
            ctx.save();
            ctx.moveTo(x, y);
            ctx.resetTransform();
            ctx.lineWidth = Math.round(this._combinedScaleFactor);
            ctx.strokeText(character, 0, 0);
            ctx.restore();
          } else {
            ctx.strokeText(character, x, y);
          }
        }
      }
      if (isAddToPathSet) {
        const paths = this.pendingTextPaths || (this.pendingTextPaths = []);
        paths.push({
          transform: ctx.mozCurrentTransform,
          x,
          y,
          fontSize,
          addToPath,
        });
      }
    }
    get isFontSubpixelAAEnabled() {