Attach (recommended) or Link to PDF file here:
https://www.canada.ca/content/dam/ircc/migration/ircc/english/pdf/kits/forms/eimm5669e.pdf
[eimm5669e.pdf](https://github.com/mozilla/pdf.js/files/7225677/eimm5669e.2.pdf)

Configuration:
- Web browser and its version: Firefox nightly
- Operating system and its version: Linux Debian

Steps to reproduce the problem:
1. Look at the bottom of page 2

constructor(attributes) {
    super(TEMPLATE_NS_ID, "area",  true);
    this.colSpan = getInteger({
      data: attributes.colSpan,
      defaultValue: 1,
      validate: n => n >= 1 || n === -1,
    });
    this.id = attributes.id || "";
    this.name = attributes.name || "";
    this.relevant = getRelevant(attributes.relevant);
    this.use = attributes.use || "";
    this.usehref = attributes.usehref || "";
    this.x = getMeasurement(attributes.x, "0pt");
    this.y = getMeasurement(attributes.y, "0pt");
    this.desc = null;
    this.extras = null;
    this.area = new XFAObjectArray();
    this.draw = new XFAObjectArray();
    this.exObject = new XFAObjectArray();
    this.exclGroup = new XFAObjectArray();
    this.field = new XFAObjectArray();
    this.subform = new XFAObjectArray();
    this.subformSet = new XFAObjectArray();
  }
  *[$getContainedChildren]() {