x-complement-fontset-spec
x-complement-fontset-spec is a compiled Lisp function in `fontset.el
'.
(x-complement-fontset-spec DEFAULT-SPEC FONTLIST)
Complement elements of FONTLIST based on DEFAULT-SPEC.
DEFAULT-SPEC is a font-spec object providing default font properties.
FONTLIST is an alist of script names vs the corresponding font names.
The font names are parsed and unspecified font properties are
given from DEFAULT-SPEC.