Thanks, it works this way.
I have created a patch for you, if the ones provided by you do not apply.

I have also created a separate patch adding multiple PARENTs to Kharoshthi
and Gothic.

On Mon, Oct 10, 2022 at 9:29 PM Visuwesh <visuweshm@gmail.com> wrote:

> [திங்கள் அக்டோபர் 10, 2022] समीर सिंह Sameer Singh wrote:
>
> > This one says: "error: corrupt patch at line 8"
> >
> > The previous one said:
> > error: patch failed: lisp/international/mule-cmds.el:1208
> > error: lisp/international/mule-cmds.el: patch does not apply
> >
>
> I have no idea why that is the case, and my network connection is too
> slow to freshly clone the Emacs repo again.  Can you replace the old
> definition of `set-language-info-alist' with the following two forms
> instead?
>
> (defun set-language-info-setup-keymap (lang-env alist describe-map
> setup-map)
>   "Setup menu items for LANG-ENV.
> See `set-language-info-alist' for details of other arguments."
>   (let ((doc (assq 'documentation alist)))
>     (when doc
>       (define-key-after describe-map (vector (intern lang-env))
>         (cons lang-env 'describe-specified-language-support))))
>   (define-key-after setup-map (vector (intern lang-env))
>     (cons lang-env 'setup-specified-language-environment)))
>
> (defun set-language-info-alist (lang-env alist &optional parents)
>   "Store ALIST as the definition of language environment LANG-ENV.
> ALIST is an alist of KEY and INFO values.  See the documentation of
> `language-info-alist' for the meanings of KEY and INFO.
>
> Optional arg PARENTS is a list of parent menu names; it specifies
> where to put this language environment in the
> Describe Language Environment and Set Language Environment menus.
> For example, (\"European\") means to put this language environment
> in the European submenu in each of those two menus."
>   (cond ((symbolp lang-env)
>          (setq lang-env (symbol-name lang-env)))
>         ((stringp lang-env)
>          (setq lang-env (purecopy lang-env))))
>   (if parents
>       (while parents
>         (let (describe-map setup-map parent-symbol parent prompt)
>           (if (symbolp (setq parent-symbol (car parents)))
>               (setq parent (symbol-name parent))
>             (setq parent parent-symbol parent-symbol (intern parent)))
>           (setq describe-map (lookup-key describe-language-environment-map
> (vector parent-symbol)))
>           ;; This prompt string is for define-prefix-command, so
>           ;; that the map it creates will be suitable for a menu.
>           (or describe-map (setq prompt (format "%s Environment" parent)))
>           (unless describe-map
>             (setq describe-map (intern (format
> "describe-%s-environment-map"
>                                                (downcase parent))))
>             (define-prefix-command describe-map nil prompt)
>             (define-key-after describe-language-environment-map (vector
> parent-symbol)
>               (cons parent describe-map)))
>           (setq setup-map (lookup-key setup-language-environment-map
> (vector parent-symbol)))
>           (unless setup-map
>             (setq setup-map (intern (format "setup-%s-environment-map"
>                                             (downcase parent))))
>             (define-prefix-command setup-map nil prompt)
>             (define-key-after setup-language-environment-map (vector
> parent-symbol)
>               (cons parent setup-map)))
>           (setq parents (cdr parents))
>           (set-language-info-setup-keymap lang-env alist (symbol-value
> describe-map) (symbol-value setup-map))))
>     (set-language-info-setup-keymap lang-env alist
>                                     describe-language-environment-map
> setup-language-environment-map))
>   (dolist (elt alist)
>     (set-language-info-internal lang-env (car elt) (cdr elt)))
>   (if (equal lang-env current-language-environment)
>       (set-language-environment lang-env)))
>