The bounding boxes of the glyphs use signed coordinates. We stored only
unsigned coordinates, which resulted in incorrect glyph positioning.
Conrecte example: the bounding box of the glyphs for clR6x12-iso-8859-5.bdf
used:
x y w h
0 -3 6 12
We on the other hand interpreted that as:
x y w h
0 65533 6 12
when loading the font from our font cache.
svn-id: r51586