bug#37806: 27.0.50; Need to "extend" face-remap.el

[Eli Zaretskii]

> From: Stephen Berman <stephen.berman@gmx.net>
> Date: Fri, 18 Oct 2019 11:14:09 +0200
> 
> 0. emacs -Q
> 1. C-x C-+ (i.e. M-x text-scale-adjust)
> 2. M-x variable-pitch-mode or M-x buffer-face-mode
> => Args out of range: [nil :family :foundry :swidth :height :weight :slant 
> :underline :inverse :foreground ...], 19
> 
> The error happens because the vector of face attributes defined in
> face-remap.el is missing the recently added :extend attribute, so it is
> too short.  This also breaks the MELPA package charmap.el (that's where
> I hit the error).  The patch below fixes this, though perhaps now would
> be a good time to do what the comment above the definition of the vector
> says: "This variable should probably be defined in C code where the
> actual definitions are available."  Or is this simple fix good enough?
> 
> (The vector is also missing the :distant-foreground attribute, so the
> patch adds that as well.  This absence happened to be innocuous because
> the first element of the vector is nil, in order to make the attribute
> indices match those of the enum lface_attribute_index defined in
> dispextern.h, so the vector was long enough; but after the addition of
> the :extend attribute, it wasn't anymore (only the indices of the vector
> are used in face-remap.el).)
> 
> In GNU Emacs 27.0.50 (build 17, x86_64-pc-linux-gnu, GTK+ Version 3.24.5, 
> cairo version 1.16.0)
>  of 2019-10-18 built on strobe-lfs84
> Repository revision: 2d13a3f68d4724af52e47675bedf60709c7b5171
> Repository branch: master
> Windowing system distributor 'The X.Org Foundation', version 11.0.12003000
> System Description: Linux From Scratch
> 
> 
> diff --git a/lisp/face-remap.el b/lisp/face-remap.el
> index 5cdecb92ee..8e565264fe 100644
> --- a/lisp/face-remap.el
> +++ b/lisp/face-remap.el
> @@ -69,7 +69,7 @@ internal-lisp-face-attributes
>    [nil
>     :family :foundry :swidth :height :weight :slant :underline :inverse
>     :foreground :background :stipple :overline :strike :box
> -   :font :inherit :fontset :vector])
> +   :font :inherit :fontset :distant :extend :vector])
> 
>  (defun face-attrs-more-relative-p (attrs1 attrs2)
>    "Return true if ATTRS1 contains a greater number of relative

Thanks.

Jimmy, could you please take a look?