bug#33114: 25.2; Emacs hangs on closing a perenthesis in a regexp in cperl mode

[Alan Mackenzie]

In article <mailman.2564.1540168987.1284.bug-gnu-emacs@gnu.org> you wrote:

> Consider the following file:

> # -*- mode: cperl -*-
> s/./(/e;

> 1. Open it with "emacs -Q".
> 2. Put the cursor just after the opening parenthesis.
> 3. Type ')' (closing parenthesis).

> This makes Emacs hang. A C-g alone has no effect. Several C-g in a row
> may give the control back to the user.

I tried this in Emacs 25.2 -Q under Gentoo.  I haven't yet been able to
reproduce the error.  Instead, on typing the ), I get the error message:

    End of `s/ ... // ... /' string/RE not found: (scan-error Unbalanced 
parentheses 29 32)

.  Maybe something in your Emacs build configuration is clashing with
something in cperl mode.

> Tested under Debian/unstable.

> In GNU Emacs 25.2.2 (x86_64-pc-linux-gnu, GTK+ Version 3.22.30)
>  of 2018-07-11, modified by Debian built on x86-ubc-01
> Windowing system distributor 'The X.Org Foundation', version 11.0.12001000
> System Description:     Debian GNU/Linux stable-updates (sid)

-- 
Alan Mackenzie (Nuremberg, Germany).