
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)


descent: signedInt16(tables.hhea.data[6], tables.hhea.data[7]),
      };
      
      this.ascent = metricsOverride.ascent / metricsOverride.unitsPerEm;
      this.descent = metricsOverride.descent / metricsOverride.unitsPerEm;
      
      if (tables.post) {
        readPostScriptTable(tables.post, properties, numGlyphs);
      }
      
      tables.post = {
        tag: "post",
        data: createPostTable(properties),
      };
      const charCodeToGlyphId = [];
      
      function hasGlyph(glyphId) {
        return !missingGlyphs[glyphId];
      }
      if (properties.composite) {
        var cidToGidMap = properties.cidToGidMap || [];
        var isCidToGidMapEmpty = cidToGidMap.length === 0;
        properties.cMap.forEach(function (charCode, cid) {
          if (cid > 0xffff) {
            throw new FormatError("Max size of CID is 65,535");
          }
          var glyphId = -1;
          if (isCidToGidMapEmpty) {
            glyphId = cid;
          } else if (cidToGidMap[cid] !== undefined) {