bug#62504: 30.0.50; SEGFAULT On M-x

[Andrea Corallo <akrl@sdf.org>]

Eli Zaretskii <eliz@gnu.org> writes:

>> From: Jacob Faibussowitsch <jacob.fai@gmail.com>
>> Date: Tue, 28 Mar 2023 11:25:49 -0400
>> 
>> This bug is twofold and appears to be related to bug#62446 and bug#61917. I produce a much smaller reproducer that generates the same kind of error as bug#61917, namely `(wrong-number-of-arguments #<subr signal> 2)`. Segfaults only occur after the following commit:
>> 
>> commit 52b67740d10df8ca539fdc2c7d50283997683141
>> Author: Mattias Engdegård <mattiase@acm.org>
>> Date:   Sat Mar 25 15:38:00 2023 +0100
>> 
>>     Generalise a LAP optimisation rule
>> 
>>     * lisp/emacs-lisp/byte-opt.el (byte-optimize-lapcode):
>>     Accept (stack-set 1) as equivalent to (discardN-preserve-tos 1) in a
>>     rule previously overlooked.  This is usually beneficial in code size
>>     and almost always shortens dynamic paths.
>> 
>> 
>> Common setup:
>> 
>> 1. mkdir repro
>> 2. Put attached init.el and main.c inside (technically, main.c need not be in repro)
>> 
>> ———
>> 
>> To reproduce bug#61917:
>> 
>> 1. git checkout master
>> 2. configure --with-native-compilation \
>>   --without-x \
>>   --without-ns \
>>   --without-compress-install \
>>   --with-native-compilation \
>>   --with-json \
>>   --with-tree-sitter
>> 3. make bootstrap
>> 4. emacs  --init-directory ../repro
>> 5. Check messages, and ye shall find the bug message.
>> 
>> ——— 
>> 
>> To reproduce segfault:
>> 
>> 1. git checkout 52b67740d10df8ca539fdc2c7d50283997683141
>> 2. Perform same configure and build commands as above.
>> 3. emacs --init-directory ../repro ../repro/main.c (loading main.c is *required*, the segfault does not fire otherwise)
>> 4. (In emacs) M-x
>> 5. Fatal error 11: Segmentation fault
>
> Thanks.
>
> Andrea, maybe this will help you investigate the issue.

Yep, noted thanks.

  Andrea