Saw clearing artifacts along the tops of characters with the Rockwell and "DIN Conden...

Saw clearing artifacts along the tops of characters with the Rockwell and "DIN Condensed" fonts in 10.14.  In both, the top of the bounding box for "@" relative to the baseline is above the reported ascent for the font.  To avoid the clearing artifacts, get the overall bounding box for the glyphs examined in updateGlyphInfo() and override the reported ascent and descent if the bounding box goes beyond that range.  There are still clearing artifacts with the "Snell Roundhand" and Zapfino fonts in 10.14, but those artifacts are on the righthand side of "@" and not along the top.