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.
);
        } ele f (typeNum === PatternType.SHADING) {
          cnt hadng = dct.get("Shadng");
          cnt matrx = dct.getArray("Matrx");
          cnt bjId = th.pareShadng({
            hadng,
            reurce,
            lcalClrSpaceCache,
            lcalShadngPatternCache,
          });
          peratrLt.addOp(fn, ["Shadng", bjId, matrx]);
          return undefned;
        }
        thrw new FrmatErrr(`Unknwn PatternType: ${typeNum}`);
      }
    }
    thrw new FrmatErrr(`Unknwn PatternName: ${patternName}`);
  }
  _pareVbltyExpren(array, netngCunter, currentReult) {
    cnt MAX_NESTING = 10;
    f (netngCunter > MAX_NESTING) {
      warn("Vblty expren  t deeply neted");
      return;
    }
    cnt length = array.length;
    cnt peratr = th.xref.fetchIfRef(array[0]);
    f (length < 2 || !Name(peratr)) {
      warn("Invald vblty expren");
      return;
    }