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 pdfDoc.getOpenAction();
        })
        .then(function (openAction) {
          expect(openAction.dest).toBeUndefined();
          expect(openAction.action).toEqual("Print");
          return loadingTask2.destroy();
        });
      await Promise.all([promise1, promise2]);
    });
    it("gets non-existent attachments", async function () {
      const attachments = await pdfDocument.getAttachments();
      expect(attachments).toEqual(null);
    });
    it("gets attachments", async function () {
      const loadingTask = getDocument(buildGetDocumentParams("attachment.pdf"));
      const pdfDoc = await loadingTask.promise;
      const attachments = await pdfDoc.getAttachments();
      const attachment = attachments["foo.txt"];
      expect(attachment.filename).toEqual("foo.txt");
      expect(attachment.content).toEqual(
        new Uint8Array([98, 97, 114, 32, 98, 97, 122, 32, 10])
      );
      await loadingTask.destroy();
    });
    it("gets javascript", async function () {
      const javascript = await pdfDocument.getJavaScript();
      expect(javascript).toEqual(null);
    });
    it("gets javascript with printing instructions (JS action)", async function () {