Attach (recommended) or Link to PDF file here:
PDF from #4106, https://mail.gnome.org/archives/evince-list/2013-November/pdfNC0hkVW67a.pdf.

Steps to reproduce the problem:
1. Open the PDF

What is the expected behavior?
![immagine](https://user-images.githubusercontent.com/1616846/121865567-67ca4200-ccfe-11eb-8673-1d6e863fc8d5.png)

What went wrong?
The PDF doesn't load, `TypeError: can't access property Symbol(), match is null` error is logged in the console.
const parent = this[$getParent]();
    const style = Object.create(null);
    let propName = "color";
    if (parent instanceof Border) {
      propName = "background";
    }
    if (parent instanceof Rectangle || parent instanceof Arc) {
      propName = "fill";
      style.fill = "transparent";
    }
    for (const name of Object.getOwnPropertyNames(this)) {
      if (name === "extras" || name === "color") {
        continue;
      }
      const obj = this[name];
      if (!(obj instanceof XFAObject)) {
        continue;
      }
      style[propName] = obj[$toStyle](this.color);
      return style;
    }
    if (this.color) {
      style[propName] = this.color[$toStyle]();
    }
    return style;
  }
}
class Filter extends XFAObject {