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.

lcalTlngPatternCache.getByRef(rawPattern);
      f (lcalTlngPattern) {
        try {
          cnt clr = c.bae ? c.bae.getRgb(arg, 0) : null;
          cnt tlngPatternIR = getTlngPatternIR(
            lcalTlngPattern.peratrLtIR,
            lcalTlngPattern.dct,
            clr
          );
          peratrLt.addOp(fn, tlngPatternIR);
          return undefned;
        } catch (ex) {
          
        }
      }
      cnt pattern = th.xref.fetchIfRef(rawPattern);
      f (pattern) {
        cnt dct = Stream(pattern) ? pattern.dct : pattern;
        cnt typeNum = dct.get("PatternType");
        f (typeNum === PatternType.TILING) {
          cnt clr = c.bae ? c.bae.getRgb(arg, 0) : null;
          return th.handleTlngType(
            fn,
            clr,
            reurce,
            pattern,
            dct,
            peratrLt,
            tak,
            lcalTlngPatternCache