Attach (recommended) or Link to PDF file here:
See pdf in https://github.com/mozilla/pdf.js/issues/3109

Configuration:
- Web browser and its version: Firefox nightly
- Operating system and its version: Windows 10
- PDF.js version: builtin viewer

Steps to reproduce the problem:
1. Look at outlines

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/141514798-0e656865-1cbf-4fb8-a89b-530d36da23c9.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/141514740-c95e0237-8bf4-4129-a4a5-cb2ea5a3f4df.png)

it("handles string values", function () {
      expect(isString("foo")).toEqual(true);
      expect(isString("")).toEqual(true);
    });
    it("handles non-string values", function () {
      expect(isString(true)).toEqual(false);
      expect(isString(1)).toEqual(false);
      expect(isString(null)).toEqual(false);
      expect(isString(undefined)).toEqual(false);
    });
  });
  describe("string32", function () {
    it("converts unsigned 32-bit integers to strings", function () {
      expect(string32(0x74727565)).toEqual("true");
      expect(string32(0x74797031)).toEqual("typ1");
      expect(string32(0x4f54544f)).toEqual("OTTO");
    });
  });
  describe("stringToBytes", function () {
    it("handles non-string arguments", function () {
      expect(function () {
        stringToBytes(null);
      }).toThrow(new Error("Invalid argument for stringToBytes"));
    });
    it("handles string arguments", function () {
      expect(stringToBytes("")).toEqual(new Uint8Array([]));
      expect(stringToBytes("foo")).toEqual(new Uint8Array([102, 111, 111]));
    });
  });
  describe("stringToPDFString", function () {