Re: [PATCH] Remove ncurses meta() call.

"Kevin J. McCarthy" <[email protected]> Fri, 26 Jun 2026 13:20:46 +0800
Newsgroups	gmane.mail.mutt.devel
Message-ID	<[email protected]>
On Fri, Jun 26, 2026 at 12:15:49AM -0400, Kurt Hackenberg wrote:
>On Thu, Jun 25, 2026 at 18:30 +0800, Kevin J. McCarthy wrote:
>
>>Ah, I figured out what foot is doing with meta enabled, (and xterm 
>>without any metaSendsEscape settings).
>>
>>If I type Alt-p, the terminal converts 'p', 0x70, to 0xF0, by 
>>flipping the high bit.  But then it encodes that in utf-8 and sends 
>>that to mutt. So mutt receives 0xC3 0xB0 in two getch() calls.
>>
>>It's a mess.
>
>That sounds like a bug in foot, or maybe a misconfiguration. It should 
>do at most one of those things, not both.

xterm does the same thing, if you remove all its configuration settings 
and run it in a utf-8 locale: converting Alt-p to 0xF0 and then utf-8 
encoding and sending that to mutt as two bytes.  It seems xterm relies 
on the "xterm.vt100.metaSendsEscape: true" setting, which is ubiquitous, 
to do Esc prefixing.  The presence of the meta() call doesn't affect 
xterm's behavior - it relies solely on the presence of that config to do 
the Esc-prefixing or not.

foot, on the other hand, does Esc-prefixing out of the box.  It is 
affected by the meta() call though, which seems to switch foot into the 
same mode that xterm has by default.  So I don't think that I have 
enough knowledge or any standing to suggest to foot they are doing the 
wrong thing.  :") It's just a matter of how they've interpreted and 
implemented smm/rmm.

>Anyway, I agree that it's probably best to remove Mutt's call to the 
>ncurses function meta().
>
>>I'm actually pondering pushing this commit to stable and releasing 
>>it with 2.4.1.  Feedback?
>
>Ehh...maybe try foot again? It really shouldn't do what you describe above.

I appreciate the note of caution, but at this point, I think it's worth 
the risk.  foot has an increasing user base, and the Debian bug(s) have 
been around for a year.  I wish I'd heard about the problem earlier.

In addition to xterm and foot, I've also tested ghostty, alacritty, 
kitty, and gnome-terminal.  Those last four seem unaffected by the 
change.  If there are other terminals anyone can suggest (that don't 
involve too many dependencies) I'll be glad to try them out too.

-- 
Kevin J. McCarthy
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