bug#28566: 25.2; show-paren error

[Eli Zaretskii]

> From: Live System User <nyc4bos@aol.com>
> Date: Sat, 23 Sep 2017 05:58:56 -0400
> 
>         I got the following backtrace error while idle when the
>         `show-paren-function`timer went off.
> 
>         I don't have a reproducible receipe so please close this
>         bug report if this information is insufficient.
> 
>         Thanks.
> 
> Debugger entered--Lisp error: (wrong-type-argument stringp t)
>   message(t)
>   (if (not (null matching-text)) (message matching-text))
>   (let ((matching-text nil)) (if (char-equal (char-syntax (or (or 
> (char-before (point)) (char-after (point))) 48)) 41) (setq matching-text 
> (blink-matching-open))) (if (not (null matching-text)) (message 
> matching-text)))
>   (let (ad-return-value) (setq ad-return-value (with-no-warnings (funcall 
> ad--addoit-function))) (let ((matching-text nil)) (if (char-equal 
> (char-syntax (or (or (char-before ...) (char-after ...)) 48)) 41) (setq 
> matching-text (blink-matching-open))) (if (not (null matching-text)) (message 
> matching-text))) ad-return-value)
>   ad-Advice-show-paren-function(#[nil "\205    \211\204\306!\210\306\f!\202\

This seems to say you have some advice installed for
show-paren-function.  As the string "matching-text" doesn't appear
anywhere in paren.el (nor anywhere else in the Emacs sources), I'm
guessing that it comes from that advice, and therefore the root cause
for the error should be looked for in that advice.

Can you tell what advice do you have for show-paren-function?