Eli Zaretskii <eliz@gnu.org> writes:

From: Jimmy Yuen Ho Wong <wyuenho@gmail.com>
Date: Thu, 18 May 2023 03:40:40 +0100


Users have discovered there's a markdown-mode function that behaves
differently depending Emacs is executing byte-compiled code or natively
compiled code.

The issue is documented
[here](https://github.com/jrblevin/markdown-mode/issues/578).


There are two examples in the issue that will produce an `Wrong type
argument: consp, nil` error on the natively compiled version of
`markdown-imenu-create-nested-index`, but not the byte-compiled or
interpreted version. A user has provided a disassembly of the natively
compiled code for that function.

The last user has said and I can confirm the offending line seems to be `(setcdr
sibling-alist alist)` in that function.

Much appreciate it if Andrea could take a look.

Adding Andrea.

While, of course, Andrea's help will be appreciated, there's currently
no reason to believe this is a problem in the Emacs core, and
therefore filing a bug report here could be premature. Ideally, the
markdown-mode's developers should examine the problem first and
present convincing evidence that this is a problem with native
compilation and not with the code in markdown-mode itself.

Yep, if markdown-mode's developers could present a reproducer showing
how exactly the function miss-behaves and where that would help.

Andrea