bug#58376: [PATCH] Set the PARENTS argument for language environments

[Visuwesh]

[ஞாயிறு அக்டோபர் 09, 2022] Eli Zaretskii wrote:

>> If I do something like:
>> 
>> (set-language-info-alist
>>  "Kharoshthi" '((charset unicode)
>>        (coding-system utf-8)
>>        (coding-priority utf-8)
>>        (input-method . "kharoshthi")
>>                 (sample-text . "Kharoṣṭhī (𐨑𐨪𐨆𐨛𐨁) 𐨣𐨨𐨲𐨪𐨆 𐨐𐨪𐨅𐨨𐨁")
>>        (documentation . "\
>> Language environment for Gāndhārī, Sanskrit, and other languages
>> using the Kharoṣṭhī script."))
>>  '("Misc" "Indian"))
>> 
>> Then compile and open emacs -Q
>> Now opening Options>Multilingual Environment>Set Language Environment>Indian
>> It only has the Kharoshthi entry
>> Options>Multilingual Environment>Set Language Environment>Misc now also has 
>> an Indian submenu with
>> only Kharoshthi entry.
>
> Hmm...  Either we don't understand what PARENTS mean (could it mean a
> hierarchy of several menu levels?), or there is a bug.
>
> If you want to work on that, please do; otherwise I'll just install
> your original patch.

Attached patch puts the "Kharosthi" item in both Indian and Misc
submenus without overwriting.

set-language-info-alist.patch
Description: Text Data

The problem is that when looping, the variables setup-map and
describe-map gets outdated and causes the overwrite.  The solution I
came up with was to update them both to their default after each
iteration.  This involved moving the keymap-setting forms to a separate
function.