Attach (recommended) or Link to PDF file here:

Configuration:
- Web browser and its version: Chrome 90.0.4430.93
- Operating system and its version: macOs Big Sur 11.2.3
- PDF.js version: 2.7.570
- Is a browser extension: No

Steps to reproduce the problem:
1. Load the attached pdf in https://mozilla.github.io/pdf.js/web/viewer.html
2. Go to page 46. Dotted lines are missing in the graphics (see screenshot from acrobat reader)

What is the expected behavior? (add screenshot) See the screenshot
[Technical_Guide_UK.pdf](https://github.com/mozilla/pdf.js/files/6413001/Technical_Guide_UK.pdf)
![Screenshot 2021-05-03 at 07 46 09](https://user-images.githubusercontent.com/3785784/116844541-a343fd80-abe3-11eb-94c3-d03b3dfd6769.png)

if (fontDirection > 0) {
        ctx.scale(textHScale, -1);
      } else {
        ctx.scale(textHScale, 1);
      }
      let lineWidth = current.lineWidth;
      let resetLineWidthToOne = false;
      const scale = current.textMatrixScale;
      if (scale === 0 || lineWidth === 0) {
        const fillStrokeMode =
          current.textRenderingMode & TextRenderingMode.FILL_STROKE_MASK;
        if (
          fillStrokeMode === TextRenderingMode.STROKE ||
          fillStrokeMode === TextRenderingMode.FILL_STROKE
        ) {
          this._cachedGetSinglePixelWidth = null;
          lineWidth = this.getSinglePixelWidth();
          resetLineWidthToOne = lineWidth < 0;
        }
      } else {
        lineWidth /= scale;
      }
      if (fontSizeScale !== 1.0) {
        ctx.scale(fontSizeScale, fontSizeScale);
        lineWidth /= fontSizeScale;
      }
      ctx.lineWidth = lineWidth;
      let x = 0,
        i;
      for (i = 0; i < glyphsLength; ++i) {