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

if (!this[$extra]) {
      const edges = this.edge.children.slice();
      if (edges.length < 4) {
        const defaultEdge = edges[edges.length - 1] || new Edge({});
        for (let i = edges.length; i < 4; i++) {
          edges.push(defaultEdge);
        }
      }
      const widths = edges.map(edge => edge.thickness);
      const insets = [0, 0, 0, 0];
      if (this.margin) {
        insets[0] = this.margin.topInset;
        insets[1] = this.margin.rightInset;
        insets[2] = this.margin.bottomInset;
        insets[3] = this.margin.leftInset;
      }
      this[$extra] = { widths, insets, edges };
    }
    return this[$extra];
  }
  [$toStyle]() {