bug#50752: 28.0.50; easy-menu-define lowers the menu-bar key

[Eli Zaretskii]

> From: Stefan Kangas <stefan@marxist.se>
> Date: Tue, 19 Oct 2021 14:54:59 -0700
> Cc: larsi@gnus.org, shuguang79@qq.com, 50752@debbugs.gnu.org
> 
> +/* Char table for the backwards-compatibility part in Flookup_key.  */
> +Lisp_Object unicode_case_table;

Should be static, I guess.

> +  /* Initialize the unicode case table, if it wasn't already.  */
> +  if (NILP (unicode_case_table))
> +    unicode_case_table = uniprop_table (intern ("lowercase"));

This is okay, but the call to staticpro should be immediately after
you call uniprop_table, so that you protect the value of the table as
it was created.  It won't work to staticpro it in syms_of_keymap,
which runs in temacs at build time.

> +       if (!STRING_MULTIBYTE (key_item))
> +         {
> +           new_item = Fdowncase (key_item);
> +         }

Style: a single statement in a block doesn't need braces.

And I guess the above assumes we resolve the issue with Turkish
locales when unibyte strings are downcased?

Otherwise, LGTM (but I didn't try applying and running the code).