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.

describe("Page", function () {
    let pdfLoadingTask, pdfDocument, page;
    beforeAll(async function () {
      pdfLoadingTask = getDocument(basicApiGetDocumentParams);
      pdfDocument = await pdfLoadingTask.promise;
      page = await pdfDocument.getPage(1);
    });
    afterAll(async function () {
      await pdfLoadingTask.destroy();
    });
    it("gets page number", function () {
      expect(page.pageNumber).toEqual(1);
    });
    it("gets rotate", function () {
      expect(page.rotate).toEqual(0);
    });
    it("gets ref", function () {
      expect(page.ref).toEqual({ num: 15, gen: 0 });
    });
    it("gets userUnit", function () {
      expect(page.userUnit).toEqual(1.0);
    });
    it("gets view", function () {
      expect(page.view).toEqual([0, 0, 595.28, 841.89]);
    });
    it("gets view, with empty/invalid bounding boxes", async function () {
      const viewLoadingTask = getDocument(
        buildGetDocumentParams("boundingBox_invalid.pdf")
      );
      const pdfDoc = await viewLoadingTask.promise;