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

[Stefan Kangas <stefan@marxist.se>]

Eli Zaretskii <eliz@gnu.org> writes:

> Unfortunately, I meant neither of these two, because they both are
> quite non-trivial.  I meant a much simpler patch which only downcases
> ASCII letters, and that's all.  Such a change doesn't need to call
> Fdowncase, and definitely doesn't need to futz with multibyte
> characters.  It should be a simple copy and a single loop downcasing
> the characters.  (The NEWS entry for emacs-28 should thus say that we
> only handle this simple class of problems.)

OK, let me just double check that you mean to memcpy and then just loop
over the memory byte by bite and update them like so:

    int new_ch = XFIXNUM (CHAR_TABLE_REF (Vascii_downcase_table, ch))

Or do you mean something even simpler like this?

    if (ch >= 'A' && ch <= 'Z')
        new_ch = c + ('A' - 'a');

> The log message should say "don't merge to master".

Hmm.  If we can live with a simpler fix on emacs-28, can we not live
with it on master as well?

Or at least live with it until we can evaluate if the simpler fix did
the job well enough?