bug#36431: Crash in marker.c:337

[Eli Zaretskii]

> Alright, so here one way to make this "transient" inconsistent state
> escape its transientness (should it be "transienticity"?) and crash Emacs:
> 
>     (catch 'toto
>       (let ((set-auto-coding-function (lambda (rest _) (throw 'toto nil))))
>         (erase-buffer)
>         (insert-file-contents "~/tmp/foo-c3c3.txt")))
>         
> where `~/tmp/foo-c3c3.txt` is a file that contains some invalid
> utf-8 byte sequence (in my case I used two bytes C3 together).

You are saying that decide_coding_unwind should do a better job?