Attach (recommended) or Link to PDF file here:
[Test file.pdf](https://github.com/mozilla/pdf.js/files/4656226/Test.file.pdf)

Configuration:
- Web browser and its version: Chrome Version 81.0.4044.138 (Official Build) (64-bit)
- Operating system and its version: Windows 10
- PDF.js version: latest
- Is a browser extension: no

Steps to reproduce the problem:
1. Open [https://mozilla.github.io/pdf.js/web/viewer.html](https://mozilla.github.io/pdf.js/web/viewer.html)
2. Load the provided .pdf file

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/5569382/82438616-02c3fe80-9aa2-11ea-9003-b75ea1e7aac6.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/5569382/82438640-09527600-9aa2-11ea-810b-071da7e37896.png)


const current = this.current;
      const font = current.font;
      const fontSize = current.fontSize;
      const fontDirection = current.fontDirection;
      const spacingDir = font.vertical ? 1 : -1;
      const charSpacing = current.charSpacing;
      const wordSpacing = current.wordSpacing;
      const textHScale = current.textHScale * fontDirection;
      const fontMatrix = current.fontMatrix || FONT_IDENTITY_MATRIX;
      const glyphsLength = glyphs.length;
      const isTextInvisible =
        current.textRenderingMode === TextRenderingMode.INVISIBLE;
      let i, glyph, width, spacingLength;
      if (isTextInvisible || fontSize === 0) {
        return;
      }
      this._cachedGetSinglePixelWidth = null;
      ctx.save();
      ctx.transform.apply(ctx, current.textMatrix);
      ctx.translate(current.x, current.y);
      ctx.scale(textHScale, fontDirection);
      for (i = 0; i < glyphsLength; ++i) {
        glyph = glyphs[i];
        if (isNum(glyph)) {
          spacingLength = (spacingDir * glyph * fontSize) / 1000;
          this.ctx.translate(spacingLength, 0);
          current.x += spacingLength * textHScale;
          continue;
        }
        const spacing = (glyph.isSpace ? wordSpacing : 0) + charSpacing;