* doc/lispref/display.texi (Low-Level Font)
<font-xlfd-name>: Document new argument `long-xlfds'.

* etc/NEWS: Mention removal of XLFD length restrictions.

* src/font.c (font_build_object): Dynamically allocate XLFD,
permitting them to surpass 255 characters in length.
(font_parse_xlfd_1): Cease rejecting XLFDs more than 255
characters in length.
(font_dynamic_unparse_xlfd): New function.  Like
font_unparse_xlfd, but allocate the XLFD dynamically.
(font_delete_unmatched): Dynamically allocate XLFD if necessary.
(Ffont_xlfd_name): New arg LONG_XLFDs.  If t, return a
dynamically allocated XLFD.  All callers changed.

* src/font.h: Update prototypes.

* src/fontset.c (Fnew_fontset): Dynamically allocate XLFD when
establishing fontset name.

* src/fontset.c (face_for_char): Display a non-ASCII character as
glyphless if the ASCII face has no fontset.  (Bug#63283)

* src/fontset.c (fontset_find_font): Add compatibility test to
registry strangeness case.
* src/sfnt.c (sfnt_read_cmap_table): Don't read subtable data if
DATA is NULL.
* src/sfntfont.c (struct sfnt_font_desc): New field `registry'.
(sfnt_registry_for_subtable): New function.
(sfntfont_identify_cmap): Move above sfnt_grok_registry.
(sfnt_grok_registry): New function.
(sfnt_enum_font_1): Call it.
(sfntfont_registries_compatible_p): New function.
(sfntfont_list_1): Check registry compatibility.
(sfntfont_registry_for_desc): New function.
(mark_sfntfont): Mark desc->registry.

* src/fontset.c (fontset_find_font): Work around TrueType
performance problem.

* lisp/faces.el (x-create-frame-with-faces): New field
`delayed-font'.  Set the `font-parameter' property to `font' in
the given parameter list after face-set-after-frame-default is
called.
* src/fontset.c (Fset_fontset_font): Avoid changing
`font-parameter' with the call to Fmodify_frame_parameters.
* src/frame.c (gui_set_frame_parameters_1): New function.
Factor out gui_set_frame_parameters here, and add an argument
DEFAULT_PARAMETER.  If the `font' parameter is set, and
`default_parameter' is not, then set the `font-parameter' frame
parameter to the `font' parameter as well, to keep track of
which user-specified `font' frame parameter set the default
face's font on the frame.
(gui_set_frame_parameters): Call gui_set_frame_parameters_1 with
new arg set to false.
(gui_set_font): Remove broken implementation of
`font-parameter'.
(gui_default_parameter): If the default value was used, then
call gui_set_frame_parameters_1 with the new argument set to
false.  This is because no font was specified as a frame
parameter by the user, so Freconsider_frame_fonts is free to do
anything it wants.
(Freconsider_frame_fonts): If `font-parameter' is set, then use
it.
(syms_of_frame): New defsym Qfont_parameter.

* src/frame.h: Update prototypes.

* src/haikuterm.c (haiku_default_font_parameter):
* src/pgtkfns.c (pgtk_default_font_parameter):
* src/w32fns.c (w32_default_font_parameter): Stop setting
`font-parameter' here.  This code resulted in decades of
automatic font rescaling not working correctly.

* src/xfaces.c (set_font_frame_param): Clear the
`font-parameter' frame parameter.
(Finternal_merge_in_global_face):
* src/xfns.c (x_default_font_parameter): Avoid changing
`font-parameter' in response to changes to face attributes.
* src/xsettings.c (apply_xft_settings): Add workaround for
Cairo.  (bug#59371, bug#59347, bug#59283, bug#59271, bug#59285,
bug#59306.)

* src/fontset.c (face_for_char): Move `eassert' to before the
fontset is really used.  Suggested by Eli Zaretskii
<eliz@gnu.org>

* doc/lispref/display.texi (Fontsets):
* src/fontset.c (Fset_fontset_font): Improve and clarify the
documentation of 'set-fontset-font'.  Rename the arguments to be
more self-explanatory.  (Bug#55086)