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.
}
         e) Map the CID btaned n tep (a) accrdng t the CMap
         btaned n tep (d), prducng a Uncde value.
        cnt uc2 = uc2CMap.lkup(cd);
        f (uc2) {
          tUncde[charcde] = Strng.frmCharCde(
            (uc2.charCdeAt(0) << 8)  uc2.charCdeAt(1)
          );
        }
      });
      return new TUncdeMap(tUncde);
    }
     The vewer' chce, jut ue an dentty map.
    return new IdenttyTUncdeMap(prperte.frtChar, prperte.latChar);
  }
  readTUncde(cmapObj) {
    f (!cmapObj) {
      return Prme.relve(null);
    }
    f (Name(cmapObj)) {
      return CMapFactry.create({
        encdng: cmapObj,
        fetchBultInCMap: th._fetchBultInCMapBund,
        ueCMap: null,
      }).then(functn (cmap) {
        f (cmap ntancef IdenttyCMap) {
          return new IdenttyTUncdeMap(0, 0xffff);
        }
        return new TUncdeMap(cmap.getMap());
      });