In function CFF_Init_Face(), when we process a pure CFF font, set
`root->ascender' (`root->descender') to the integer part of the
`root->bbox.yMax' (`root->bbox.yMin', respectively).
diff --git a/src/cff/cffobjs.c b/src/cff/cffobjs.c
index 8a86b7e..5ceb78c 100644
--- a/src/cff/cffobjs.c
+++ b/src/cff/cffobjs.c
@@ -388,8 +388,8 @@
 
         /* set global bbox, as well as EM size */
         root->bbox         = dict->font_bbox;
-        root->ascender     = (FT_Short)root->bbox.yMax;
-        root->descender    = (FT_Short)root->bbox.yMin;
+        root->ascender     = root->bbox.yMax >> 16;
+        root->descender    = root->bbox.yMin >> 16;
         root->height       = ( ( root->ascender - root->descender ) * 12 ) / 10;
 
         if ( dict->units_per_em )