Attach (recommended) or Link to PDF file here:
https://www.nta.go.jp/taxes/tetsuzuki/shinsei/annai/joyaku/annai/pdf2/250.pdf

Configuration:
- Web browser and its version: Firefox 81.0a1
- Operating system and its version: Debian 5.6.7-1
- PDF.js version: latest in Firefox nightly
- Is a browser extension: No

Steps to reproduce the problem:
1. Open the pdf and paste the following text "本 店 又 は 主 た る 事 務 所 の 所 在 地" in "Full name" and in "Domicile and residence" textfields
2. Print or Save the pdf 

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/91207547-30f05480-e709-11ea-9abd-2af5d970dc46.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/91207663-69902e00-e709-11ea-8a1d-1ddd30cf0621.png)

Link to a viewer (if hosted on a site other than mozilla.github.io/pdf.js or as Firefox/Chrome extension):

return annotation.getFieldObject();
        })
        .then(object => {
          const actions = object.actions;
          expect(actions.MouseEnter).toEqual(["hello()"]);
          expect(actions.MouseExit).toEqual([
            "world()",
            "olleh()",
            "foo()",
            "dlrow()",
            "oof()",
          ]);
          expect(actions.MouseDown).toEqual(["bar()"]);
          done();
        }, done.fail);
    });
  });
  describe("ButtonWidgetAnnotation", function () {
    let buttonWidgetDict;
    beforeEach(function (done) {
      buttonWidgetDict = new Dict();
      buttonWidgetDict.set("Type", Name.get("Annot"));
      buttonWidgetDict.set("Subtype", Name.get("Widget"));
      buttonWidgetDict.set("FT", Name.get("Btn"));
      done();
    });
    afterEach(function () {
      buttonWidgetDict = null;
    });
    it("should handle checkboxes with export value", function (done) {