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.
if (useCache) {
        cached = somCache.get(node);
        if (!cached) {
          cached = new Map();
          somCache.set(node, cached);
        }
        children = cached.get(cacheName);
      }
      if (!children) {
        switch (operator) {
          case operators.dot:
            children = node[$getChildrenByName](name, false);
            break;
          case operators.dotDot:
            children = node[$getChildrenByName](name, true);
            break;
          case operators.dotHash:
            children = node[$getChildrenByClass](name);
            if (children instanceof XFAObjectArray) {
              children = children.children;
            } else {
              children = [children];
            }
            break;
          default:
            break;
        }
        if (useCache) {
          cached.set(cacheName, children);
        }