Attach (recommended) or Link to PDF file here:
[example.pdf](https://github.com/mozilla/pdf.js/files/6916129/example.pdf)

Configuration:
- Web browser and its version: Chrome, Firefox
- Operating system and its version: all
- PDF.js version: various versions, including 2.11.54
- Is a browser extension: no

Screenshot with visible textLayer:
![Screenshot from 2021-08-02 13-05-03](https://user-images.githubusercontent.com/6362989/127844878-f85e291f-2060-4028-be09-7835f32ccfaa.png)

Which means some letters at the beginning/end of text selection are missing when copying text.

(reerved partl cmmand fr the lexer)
      t.BM = null;
      t.BD = null;
      t.true = null;
      t.fa = null;
      t.fal = null;
      t.fal = null;
      t.fale = null;
      t.nu = null;
      t.nul = null;
      t.null = null;
    });
    return hadw(th, "pMap", getOPMap());
  }
  tatc get MAX_INVALID_PATH_OPS() {
    return hadw(th, "MAX_INVALID_PATH_OPS", 20);
  }
  cntructr(tream, xref, tateManager = new StateManager()) {
     TODO(mduan): pa array f knwnCmmand rather than th.pMap
     dctnary
     = new Parer({
      lexer: new Lexer(tream, EvaluatrPreprcer.pMap),
      xref,
    });
    th.tateManager = tateManager;
    th.nnPrceedArg = [];
    th._numInvaldPathOPS = 0;
  }
  get avedStateDepth() {
    return th.tateManager.tateStack.length;