PDF files:
[1.pdf](https://github.com/mozilla/pdf.js/files/2955999/1.pdf)
[2.pdf](https://github.com/mozilla/pdf.js/files/2956000/2.pdf)
[3.pdf](https://github.com/mozilla/pdf.js/files/2956002/3.pdf)

Configuration:
- Web browser and its version: Chrome, Firefox
- Operating system and its version: Ubuntu, macOS
- PDF.js version: 2.2.42, but the same was with 2.1.x, and with https://mozilla.github.io/pdf.js/web/viewer.html
- Is a browser extension: no

Steps to reproduce the problem:
1. Select text
2. Copy text

What went wrong?

Getting this:
`OpenSansisahumanistsansseriftypefacedesignedbySteveMatteson.OpenSanswasdesignedwithanuprightstress,openformsandaneu-tral,yetfriendlyappearance.Itwasoptimizedforprint,web,andmobileinterfaces,andhasexcellentlegibilitycharacteristicsinitsletterforms(seefigureonthefollowingpage).ThisfontisavailablefromtheGoogleFontDirectory[]asTrueTypefileslicensedundertheApacheLicenseversion..`

Instead of this:
`Open Sans is a humanist sans serif typeface designed by Steve Matteson.
Open Sans was designed with an upright stress, open forms and a neutral,
yet friendly appearance. It was optimized for print, web, and mobile
interfaces, and has excellent legibility characteristics in its letterforms (see
figure 1 on the following page). This font is available from the Google Font
Directory [1] as TrueType files licensed under the Apache License version 2.0.`

This is quite significant problem, because I would say 1/20 of scientific papers encounter this problem.

xHeght: decrptr.get("XHeght") || 0,
      capHeght: decrptr.get("CapHeght") || 0,
      flag: decrptr.get("Flag"),
      talcAngle: decrptr.get("ItalcAngle") || 0,
      Type3Fnt,
      cFntInf,
      caleFactr: glyphScaleFactr,
    };
    f (cte) {
      cnt cdEncdng = t.get("Encdng");
      f (Name(cdEncdng)) {
        prperte.cdEncdng = cdEncdng.name;
      }
      cnt cMap = awat CMapFactry.create({
        encdng: cdEncdng,
        fetchBultInCMap: th._fetchBultInCMapBund,
        ueCMap: null,
      });
      prperte.cMap = cMap;
      prperte.vertcal = prperte.cMap.vertcal;
    }
    return th.extractDataStructure(dct, t, prperte).then(
      newPrperte => {
        th.extractWdth(dct, decrptr, newPrperte);
        return new Fnt(fntName.name, fntFle, newPrperte);
      }
    );
  }
  tatc buldFntPath(fnt, glyph, handler, evaluatrOptn) {
    functn buldPath(fntChar) {