
Attach (recommended) or Link to PDF file here:
[NAPEN16171380959.pdf](https://github.com/mozilla/pdf.js/files/6143802/NAPEN16171380959.pdf)

Configuration:
- Web browser and its version: Firefox 88 Nightly
- Operating system and its version: Windows 10
- PDF.js version:
- Is a browser extension: No

What went wrong? (add screenshot)
![](https://user-media-prod-cdn.itsre-sumo.mozilla.net/uploads/images/2021-03-15-10-58-27-ce2796.png)


var charCodeToGlyphId = Object.create(null);
  var glyphId, charCode, baseEncoding;
  var isSymbolicFont = !!(properties.flags & FontFlags.Symbolic);
  if (properties.baseEncodingName) {
    
    
    baseEncoding = getEncoding(properties.baseEncodingName);
    for (charCode = 0; charCode < baseEncoding.length; charCode++) {
      glyphId = glyphNames.indexOf(baseEncoding[charCode]);
      if (glyphId >= 0) {
        charCodeToGlyphId[charCode] = glyphId;
      } else {
        charCodeToGlyphId[charCode] = 0; 
      }
    }
  } else if (isSymbolicFont) {
    
    for (charCode in builtInEncoding) {
      charCodeToGlyphId[charCode] = builtInEncoding[charCode];
    }
  } else {
    
    
    baseEncoding = StandardEncoding;
    for (charCode = 0; charCode < baseEncoding.length; charCode++) {
      glyphId = glyphNames.indexOf(baseEncoding[charCode]);
      if (glyphId >= 0) {
        charCodeToGlyphId[charCode] = glyphId;
      } else {
        charCodeToGlyphId[charCode] = 0;