bug#71337: 30.0.50; `electric-pair-mode' and custom keybinding

[Stephen Berman via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

On Tue, 4 Jun 2024 09:08:51 +0100 João Távora <joaotavora@gmail.com> wrote:

> On Tue, Jun 4, 2024 at 8:37 AM João Távora <joaotavora@gmail.com> wrote:
>>
>> On Tue, Jun 4, 2024 at 8:30 AM Stephen Berman <stephen.berman@gmx.net> wrote:
>> >
>> > On Tue, 04 Jun 2024 07:53:16 +0200 Arash Esbati <arash@gnu.org> wrote:
>> >
>> > > Stephen Berman <stephen.berman@gmx.net> writes:
>> > >
>> > >> If the pairing in electric-pair-mode should only be triggered by
>> > >> self-inserting characters (as the current code seems to require), then
>> > >> the attached patch appears to avoid the above problem.
>> > >
>> > > Thanks for your response.  Yes, your patch fixes the issue.  Do you want
>> > > to install it?
>> >
>> > I think it would be prudent to wait for someone familiar with the
>> > electric-pair-mode implementation (e.g. its author João Távora, Cc'd),
>> > or failing that, an Emacs maintainer, to ok the patch.
>>
>> I will have a look if I can.  It would also be prudent to make sure
>> the unit tests all pass, like they presumably do before the patch.
>
> I've had a look.  it looks like the problems is e-p-mode's assumption
> that last-command-event is the thing to be inserted.  The fact that
> it isn't here (somehow an innocent 92 is now a monstrous 8388643),
> triggers the problem (8388643 isn't a representation of a character,
> apparently).

Right, because (max-char) => 4194303 (#o17777777, #x3fffff)

> But according to the docstring of post-self-insert-hook,
> the assumption seems sane, and I probably coded for it.

That's what I thought, too.

>   post-self-insert-hook is a variable defined in `src/cmds.c'.
>
>   ...
>
>   The hook can access the inserted character via `last-command-event'.
>   ...
>
> I don't think the patch is fully correct.  I think Stefan is the right
> person to call here.  I've had an even briefer look at cmds.c and I
> don't understand how that hook's promise is honoured.

Thanks for taking a look.

Steve Berman