bug#67600: [PATCH] Add dashes to 'thing-at-point-email-regexp'

[Visuwesh]

[Tuesday December 12, 2023] Eli Zaretskii wrote:

>> From: Visuwesh <visuweshm@gmail.com>
>> Cc: Philip Kaludercic <philipk@posteo.net>,  67600@debbugs.gnu.org
>> Date: Tue, 12 Dec 2023 17:51:32 +0530
>> 
>> [Tuesday December 12, 2023] Eli Zaretskii wrote:
>> 
>> > Thanks.
>> >
>> > My bother here is that this could cause false positives whereby
>> > thing-at-point would recognize file names with slashes as email
>> > addresses.  Because otherwise I don't understand why the slash was
>> > omitted in the first place.  Can we somehow make sure this won't
>> > happen?
>> 
>> I am running Emacs with the same change before Philip created this bug
>> report and so far I haven't had false positives for email addresses
>> because files with a @ in its name is rare.  In practise, I think this
>> patch is harmless in that regard.
>
> Remote files that have user@host in their names do have that
> character.

AFAIU, user cannot have slashes in them as per the POSIX standards [1]
and likewise with hostname so remote files should not pose a problem.
Of course this assumes that you're only looking at methods like ssh,
doas, sudo, etc.  It seems like tramp disallows slashes in user and host
anyway, try:

    (file-remote-p "/ssh:userwith/@host:/") ;; => nil
    (file-remote-p "/ssh:userwith@host/:/") ;; => nil
    (file-remote-p "/ssh:userwith@host:/") ;; => /ssh:userwith@host:

1. https://serverfault.com/a/578264