Attach (recommended) or Link to PDF file here:
https://bitcoin.org/bitcoin.pdf

Configuration:
- Web browser and its version: all
- Operating system and its version: all
- PDF.js version: tested with 2.9.11, but most likely all versions
- Is a browser extension: no

Steps to reproduce the problem:
1. Type "a purely" (single space between "a" and "purely") - doesn't find anything
2. Type "a  purely" (two spaces between "a" and "purely") - finds the phrase

Sometimes even 3 spaces are necessary.

What is the expected behavior? (add screenshot)
![Screenshot from 2021-04-08 13-00-03](https://user-images.githubusercontent.com/6362989/114008903-57639a00-986b-11eb-903a-92bbebbd922b.png)

What went wrong? (add screenshot)
![Screenshot from 2021-04-08 13-01-53](https://user-images.githubusercontent.com/6362989/114008810-44e96080-986b-11eb-8232-f58a62ed7899.png)

This affects many PDFs because justify alignment is common enough.
return loadingTask.destroy();
      });
      await Promise.all(destroyPromises);
    });
    it("should correctly render PDFs in parallel", async function () {
      let baseline1, baseline2, baseline3;
      const promiseDone = renderPDF(pdf1)
        .then(function (data1) {
          baseline1 = data1;
          return renderPDF(pdf2);
        })
        .then(function (data2) {
          baseline2 = data2;
          return renderPDF(pdf3);
        })
        .then(function (data3) {
          baseline3 = data3;
          return Promise.all([
            renderPDF(pdf1),
            renderPDF(pdf2),
            renderPDF(pdf3),
          ]);
        })
        .then(function (dataUrls) {
          expect(dataUrls[0]).toEqual(baseline1);
          expect(dataUrls[1]).toEqual(baseline2);
          expect(dataUrls[2]).toEqual(baseline3);
          return true;
        });
      await promiseDone;