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

const parent = this[$getParent]();
    const grandpa = parent[$getParent]();
    const ggrandpa = grandpa[$getParent]();
    const style = Object.create(null);
    
    let propName = "color";
    
    let altPropName = propName;
    if (parent instanceof Border) {
      propName = "background-color";
      altPropName = "background";
      if (ggrandpa instanceof Ui) {