bug#38287: 26.3.50; filenotify.el: the Chinese file name in the event is messy code

[Michael Albinus]

Eli Zaretskii <eliz@gnu.org> writes:

>> Hmm. kqueue.c is very lazy in using ENCODE_FILE, it uses it only in
>> kqueue-add-watch. Maybe it is missing somewhere else?
>
> I see one potential problem: in kqueue-add-watch, you encode the file
> name, but then pass it to APIs that generally expect multibyte
> (i.e. un-encoded) strings, although they will also work with encoded
> unibyte strings.  Moreover, you put the unibyte encoded file name into
> the watch object.  Not sure if this is related to the issue at hand,
> but it would be cleaner to make this change:
>
> diff --git a/src/kqueue.c b/src/kqueue.c
> index 76d7fc1..1383d7d 100644
> --- a/src/kqueue.c
> +++ b/src/kqueue.c
> @@ -414,7 +414,7 @@ DEFUN ("kqueue-add-watch", Fkqueue_add_watch, 
> Skqueue_add_watch, 3, 3, 0,
>      }
>
>    /* Open file.  */
> -  file = ENCODE_FILE (file);
> +  Lisp_Object encoded_file = ENCODE_FILE (file);
>    oflags = O_NONBLOCK;
>  #if O_EVTONLY
>    oflags |= O_EVTONLY;
> @@ -426,7 +426,7 @@ DEFUN ("kqueue-add-watch", Fkqueue_add_watch, 
> Skqueue_add_watch, 3, 3, 0,
>  #else
>      oflags |= O_NOFOLLOW;
>  #endif
> -  fd = emacs_open (SSDATA (file), oflags, 0);
> +  fd = emacs_open (SSDATA (encoded_file), oflags, 0);
>    if (fd == -1)
>      report_file_error ("File cannot be opened", file);

Thanks, let's see how far we go with this.

> Btw, I don't think I understand the nature of the problem yet: where
> were the unibyte strings shown in the report printed?  Did some Emacs
> code print them, and if so, where is that code?

Same question here. Looks like the OP has added some prints to the code.

In Emacs 27.0.50, we have file-notify-debug, which does it for us when
set to t. But this is Emacs 26.3.50, that's why I have asked to activate
the relevant debug message manually.

Best regards, Michael.