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From: Andreas Schwab <schwab@linux-m68k.org>
To: Lars Ingebrigtsen <larsi@gnus.org>
Cc: Christian Johansson <christian@cvj.se>, 53680@debbugs.gnu.org
Subject: bug#53680: Endless loop in peculiar case of string-match and string-match-p 27.02 and 28.0.50
Date: Tue, 01 Feb 2022 12:15:43 +0100	[thread overview]
Message-ID: <87pmo63kio.fsf@igel.home> (raw)
In-Reply-To: <8735l2x35t.fsf@gnus.org> (Lars Ingebrigtsen's message of "Tue, 01 Feb 2022 12:00:14 +0100")

On Feb 01 2022, Lars Ingebrigtsen wrote:

> I guess the · are supposed to be spaces, so it's:
>
> (string-match
>  "[\r\t ]*implements[\r\t ]+\\([\r\t ]*[\\a-zA-Z_0-9_]+,?\\)+[\r\t ]*{$"
>  "ariable implements \\Magento\\Framework\\Event\\OberserverInterface\r{\r    public function __construct()\r ")
>
> And I can reproduce this on master, too.  Is it a problem with excessive
> backtracking, perhaps?

It sure is.  The nesting of the + operator without proper anchoring
makes the search space explode.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 7578 EB47 D4E5 4D69 2510  2552 DF73 E780 A9DA AEC1
"And now for something completely different."





  parent reply	other threads:[~2022-02-01 11:15 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-02-01  7:37 bug#53680: Endless loop in peculiar case of string-match and string-match-p 27.02 and 28.0.50 Christian Johansson
2022-02-01 11:00 ` Lars Ingebrigtsen
2022-02-01 11:08   ` Lars Ingebrigtsen
2022-02-01 11:25     ` Andreas Schwab
2022-02-01 11:15   ` Andreas Schwab [this message]
2022-02-01 12:16     ` Lars Ingebrigtsen
2022-02-01 12:56 ` Mattias Engdegård
2022-02-01 13:12   ` Christian Johansson
     [not found]     ` <AB866492-4CC0-418A-8C9E-CAAB2C522CDA@acm.org>
2022-02-01 16:23       ` Christian Johansson

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