Viewer:  https://mozilla.github.io/pdf.js/web/viewer.html
Chrome on Windows 10
When the attached PDF file is viewed, some of the fonts display as garbled text. 
[Arial, Courier, Times New Roman]
The file views correctly in Adobe Reader.
[fff.pdf](https://github.com/mozilla/pdf.js/files/4652174/fff.pdf)

const firstEntryLength = itemDecode(locaData, itemSize);
        if (newGlyfData.length > firstEntryLength + writeOffset) {
          glyf.data = newGlyfData.subarray(0, firstEntryLength + writeOffset);
        } else {
          glyf.data = new Uint8Array(firstEntryLength + writeOffset);
          glyf.data.set(newGlyfData.subarray(0, writeOffset));
        }
        glyf.data.set(newGlyfData.subarray(0, firstEntryLength), writeOffset);
        itemEncode(
          loca.data,
          locaData.length - itemSize,
          writeOffset + firstEntryLength
        );
      } else {
        glyf.data = newGlyfData.subarray(0, writeOffset);
      }
      return {
        missingGlyphs,
        maxSizeOfInstructions,
      };
    }
    function readPostScriptTable(post, propertiesObj, maxpNumGlyphs) {
      const start = (font.start ? font.start : 0) + post.offset;
      font.pos = start;
      const length = post.length,
        end = start + length;
      const version = font.getInt32();