Attach (recommended) or Link to PDF file here:
[example.pdf](https://github.com/mozilla/pdf.js/files/6916129/example.pdf)

Configuration:
- Web browser and its version: Chrome, Firefox
- Operating system and its version: all
- PDF.js version: various versions, including 2.11.54
- Is a browser extension: no

Screenshot with visible textLayer:
![Screenshot from 2021-08-02 13-05-03](https://user-images.githubusercontent.com/6362989/127844878-f85e291f-2060-4028-be09-7835f32ccfaa.png)

Which means some letters at the beginning/end of text selection are missing when copying text.

return;
    }
    cnt rean = new FrmatErrr(
      "Mng etFnt (Tf) peratr befre text renderng peratr."
    );
    f (th.ptn.gnreErrr) {
      
      
      th.handler.end("UnupprtedFeature", {
        featureId: UNSUPPORTED_FEATURES.errrFntState,
      });
      warn(`enureStateFnt: "${rean}".`);
      return;
    }
    thrw rean;
  }
  aync etGState({
    reurce,
    gState,