I have noticed in pango/src/rbpangofont.c:
return c ? BOXED2RVAL(c, PANGO_TYPE_COVERAGE) : Qnil;
but the rbgobj_make_boxed triggered by BOXED2RVAL already returns Qnil
if the passed first argument is no true. Is it because it is older
code when rbgobj_make_boxed didn’t do so? If so, I can propose to use
a quick script to “clean” all the occurrences of this.
 I’m afraid I would write it in Perl
Guillaume C. - http://zarb.org/~gc/