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.

return loadingTask.promise
          .then(function (pdf) {
            return pdf.destroy();
          })
          .then(
            function () {
              expect(expectSuccess).toEqual(true);
            },
            function (error) {
              if (expectSuccess) {
                
                expect(error).toEqual("There should not be any error");
              }
              expect(expectSuccess).toEqual(false);
            }
          );
      }
      function testCanLoad(filename, options) {
        return _checkCanLoad(true, filename, options);
      }
      function testCannotLoad(filename, options) {
        return _checkCanLoad(false, filename, options);
      }
      afterEach(async function () {
        if (loadingTask && !loadingTask.destroyed) {
          await loadingTask.destroy();
        }
      });
      it("server disallows cors", async function () {
        await testCannotLoad("basicapi.pdf");