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

Configuration:
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- 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)


adjustToUnicode(properties, properties.builtInEncoding);
      }
      
      
      
      let glyphZeroId = 1;
      if (font instanceof CFFFont) {
        glyphZeroId = font.numGlyphs - 1;
      }
      var mapping = font.getGlyphMapping(properties);
      var newMapping = adjustMapping(
        mapping,
        font.hasGlyphId.bind(font),
        glyphZeroId
      );
      this.toFontChar = newMapping.toFontChar;
      var numGlyphs = font.numGlyphs;
      function getCharCodes(charCodeToGlyphId, glyphId) {
        var charCodes = null;
        for (var charCode in charCodeToGlyphId) {
          if (glyphId === charCodeToGlyphId[charCode]) {
            if (!charCodes) {
              charCodes = [];
            }
            charCodes.push(charCode | 0);
          }
        }
        return charCodes;
      }
      function createCharCode(charCodeToGlyphId, glyphId) {