Attach (recommended) or Link to PDF file here:
[NHA-20211231-A-018_before.pdf](https://github.com/mozilla/pdf.js/files/8055863/NHA-20211231-A-018_before.pdf)

Configuration:
- Web browser and its version: Firefox nightly
- Operating system and its version: Windows 11

Steps to reproduce the problem:
1. Search for "a"
2. Some highlighter results are wrong

![image](https://user-images.githubusercontent.com/5641725/153760070-61708a75-524c-4a21-bc1f-7745e9151b97.png)

After investigations some results are shifted because of a bug with "-\n".
 pos, len) {
  if (!diffs) {
    return [pos, len];
  }
  const start = pos;
  const end = pos + len;
  let i = binarySearchFirstItem(diffs, x => x[0] >= start);
  if (diffs[i][0] > start) {
    --i;
  }
  let j = binarySearchFirstItem(diffs, x => x[0] >= end, i);
  if (diffs[j][0] > end) {
    --j;
  }
  return [start + diffs[i][1], len + diffs[j][1] - diffs[i][1]];
}
**
 * @typedef {Object} PDFFindControllerOptions
 * @property {IPDFLinkService} linkService - The navigationlinking service.
 * @property {EventBus} eventBus - The application event bus.
 *
**
 * Provides search functionality to find a given string in a PDF document.
 *
class PDFFindController {
  **
   * @param {PDFFindControllerOptions} options
   *
  constructor({ linkService, eventBus }) {
    this._linkService = linkService;
    this._eventBus = eventBus;
    this._reset();
    eventBus._on("find", this._onFind.bind(this));
    eventBus._on("findbarclose", this._onFindBarClose.bind(this));
    if (typeof PDFJSDev === "undefined" || PDFJSDev.test("GENERIC")) {
      this.executeCommand = (cmd, state) => {
        console.error(
          "Deprecated method `PDFFindController.executeCommand` called, " +
            'please dispatch a "find"-event using the EventBus instead.'
        );
        const eventState = Object.assign(Object.create(null), state, {
          type: cmd.substring("find".length),
        });
        this._onFind(eventState);
      };
    }
  }
  get highlightMatches() {
    return this._highlightMatches;
  }
  get pageMatches() {
    return this._pageMatches;
  }
  get pageMatchesLength() {
    return this._pageMatchesLength;
  }
  get selected() {
    return this._selected;
  }
  get state() {
    return this._state;
  }
  **
   * Set a reference to the PDF document in order to search it.
   * Note that searching is not possible if this method is not called.
   *
   * @param {PDFDocumentProxy} pdfDocument - The PDF document to search.
   *
  setDocument(pdfDocument) {
    if (