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.
PasswordException,
  PasswordResponses,
  PermissionFlag,
  StreamType,
} from "../../src/shared/util.js";
import {
  buildGetDocumentParams,
  DefaultFileReaderFactory,
  TEST_PDFS_PATH,
} from "./test_utils.js";
import {
  DefaultCanvasFactory,
  getDocument,
  PDFDataRangeTransport,
  PDFDocumentLoadingTask,
  PDFDocumentProxy,
  PDFPageProxy,
  PDFWorker,
  RenderTask,
} from "../../src/display/api.js";
import {
  RenderingCancelledException,
  StatTimer,
} from "../../src/display/display_utils.js";
import { AutoPrintRegExp } from "../../web/ui_utils.js";
import { GlobalImageCache } from "../../src/core/image_utils.js";
import { GlobalWorkerOptions } from "../../src/display/worker_options.js";
import { isNodeJS } from "../../src/shared/is_node.js";
import { Metadata } from "../../src/display/metadata.js";
describe("api", function () {