Subject: bug#60711: Compose fails to generate ≤ and ≥ (only those two! and only in emacs!)

From: Po Lu <[email-masked]>
Date: Wed, 11 Jan 2023 15:29:05 +0800

Gregory Heytings <[email-masked]> writes:

>>
>> Since some recent emacs update (version below):
>>
>> a) I can no longer generate ≤ and ≥ in Emacs
>>
>> All combinations (Compose >=, Compose >_, Compose _>) end the same:
>> - after entering Compose > there is floating window hinting ≥
>> - once I type =, puff, no character in the buffer, nothing.
>>
>
> It's unlikely that this is an Emacs bug, Emacs does not "see" anything
> until the compose sequence is finished, it only sees the final
> character.

Not exactly true.

Composition involves a whole bunch of code in xterm.c.  I guess these
days composition is mostly implemented in an input method, so all the
communication with the input method (forwarding and waiting for events,
for example) implemented in xterm.c and Xlib is also suspect.

> What's that "floating window" you mention?
>
> What does Emacs tell you when you type "C-h k Compose _ >"?

So if this doesn't show anything meaningful, would you please see what
KeyPress events are received by Emacs while you are typing the compose
sequence, and after _> should have been inserted?  (Place the breakpoint
in handle_one_xevent, because at that point events have already been
filtered.  This is assuming you're really using Emacs 28.1, of course.
The code has been rewritten in Emacs 29.)