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.

expect(outlineItemTwo.url).toEqual("http://google.com/");
      expect(outlineItemTwo.unsafeUrl).toEqual("http://google.com");
      expect(outlineItemTwo.newWindow).toBeUndefined();
      const outlineItemOne = outline[1];
      expect(outlineItemOne.bold).toEqual(false);
      expect(outlineItemOne.italic).toEqual(true);
      expect(outlineItemOne.color).toEqual(new Uint8ClampedArray([0, 0, 0]));
      await loadingTask.destroy();
    });
    it("gets non-existent permissions", async function () {
      const permissions = await pdfDocument.getPermissions();
      expect(permissions).toEqual(null);
    });
    it("gets permissions", async function () {
      
      const loadingTask0 = getDocument(
        buildGetDocumentParams("issue9972-1.pdf")
      );
      const promise0 = loadingTask0.promise.then(function (pdfDoc) {
        return pdfDoc.getPermissions();
      });
      
      const loadingTask1 = getDocument(
        buildGetDocumentParams("issue9972-2.pdf")
      );
      const promise1 = loadingTask1.promise.then(function (pdfDoc) {
        return pdfDoc.getPermissions();
      });
      
      const loadingTask2 = getDocument(