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From: Eric Abrahamsen <eric@ericabrahamsen.net>
To: help-gnu-emacs@gnu.org
Subject: More confusion about multibyte vs unibyte strings
Date: Thu, 05 May 2022 09:58:43 -0700	[thread overview]
Message-ID: <874k23or0c.fsf@ericabrahamsen.net> (raw)

In gnus-search.el, we do some work on search strings before sending them
to an IMAP server as a query: there are particular formats that need to
be used depending on whether the string is plain ASCII, or needs to be
encoded as UTF-8 or something. From the code itself:

(gnus-search-imap-handle-string
 (make-instance 'gnus-search-imap :literal-plus t)
 "FROM eric")

-> "FROM eric"

(gnus-search-imap-handle-string
 (make-instance 'gnus-search-imap :literal-plus t)
 "FROM 张三")

-> "{11+}
FROM \345\274\240\344\270\211"

The function above uses `multibyte-string-p' to test whether the string
needs the extra handling. This works correctly in the minibuffer and
*scratch*:

(multibyte-string-p "FROM eric") -> nil

(multibyte-string-p "FROM 张三") -> t

but when I edebug the code during an actual IMAP search, the test
returns t for both strings, which messes things up.

I must be using it wrong! But I don't understand why. What can change in
the evaluation environment such that the calls to `multibyte-string-p'
would return different results at different times? And what check
*should* I be using to see if a string is pure ASCII?

Thanks,
Eric




             reply	other threads:[~2022-05-05 16:58 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-05-05 16:58 Eric Abrahamsen [this message]
2022-05-05 17:34 ` More confusion about multibyte vs unibyte strings Eli Zaretskii
2022-05-05 18:44   ` Eric Abrahamsen
2022-05-05 19:23     ` Eli Zaretskii
2022-05-06  0:45       ` Eric Abrahamsen
2022-05-06  2:58         ` Stefan Monnier via Users list for the GNU Emacs text editor
2022-05-06 16:45           ` Eric Abrahamsen
2022-05-06 17:39             ` Stefan Monnier via Users list for the GNU Emacs text editor
2022-05-06 18:02               ` Eric Abrahamsen

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