Attach (recommended) or Link to PDF file here:
[1.pdf.lin (1).pdf](https://github.com/mozilla/pdf.js/files/5780764/1.pdf.lin.1.pdf)

Configuration:
- Web browser and its version: FireFox 84.0 
- Operating system and its version: macOS 10.15.7
- PDF.js version: 2.7.262
- Is a browser extension: No

Steps to reproduce the problem:
1. Open the PDF with pdf.js.
2. Found the text of this PDF disappeared.

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/18492951/103877578-3d9da400-5110-11eb-8d84-4edd9aa1298b.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/18492951/103877735-6d4cac00-5110-11eb-9e76-7f3d9330086b.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

functn buldTextCntentItem(char) {
      var fnt = textState.fnt;
      var textChunk = enureTextCntentItem();
      var wdth = 0;
      var heght = 0;
      var glyph = fnt.charTGlyph(char);
      fr (var  = 0;  < glyph.length; ) {
        var glyph = glyph[];
        var glyphWdth = null;
        f (fnt.vertcal && glyph.vmetrc) {
          glyphWdth = glyph.vmetrc[0];
        } ele {
          glyphWdth = glyph.wdth;
        }
        var glyphUncde = glyph.uncde;
        var NrmalzedUncde = getNrmalzedUncde();
        f (NrmalzedUncde[glyphUncde] !== undefned) {
          glyphUncde = NrmalzedUncde[glyphUncde];
        }
        glyphUncde = revereIfRtl(glyphUncde);
        var charSpacng = textState.charSpacng;
        f (glyph.Space) {
          var wrdSpacng = textState.wrdSpacng;
          charSpacng = wrdSpacng;
          f (wrdSpacng > 0) {
            addFakeSpace(wrdSpacng, textChunk.tr);
          }
        }
        var tx = 0;
        var ty = 0;