Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > gnu.bash.bug > #15988

Re: Change in SIGTERM behaviour in bash 4.3 when using readline

Path csiph.com!goblin1!goblin.stu.neva.ru!usenet.stanford.edu!not-for-mail
From Chris Down <chris@chrisdown.name>
Newsgroups gnu.bash.bug
Subject Re: Change in SIGTERM behaviour in bash 4.3 when using readline
Date Wed, 4 Mar 2020 19:29:18 +0000
Lines 17
Approved bug-bash@gnu.org
Message-ID <mailman.2049.1583350164.2412.bug-bash@gnu.org> (permalink)
References <20200304181824.GA394387@chrisdown.name> <20200304192918.GB394387@chrisdown.name>
NNTP-Posting-Host lists.gnu.org
Mime-Version 1.0
Content-Type text/plain; charset=us-ascii; format=flowed
X-Trace usenet.stanford.edu 1583350164 32271 209.51.188.17 (4 Mar 2020 19:29:24 GMT)
X-Complaints-To action@cs.stanford.edu
To bug-bash@gnu.org
Envelope-to bug-bash@gnu.org
DKIM-Signature v=1; a=rsa-sha256; c=relaxed/relaxed; d=chrisdown.name; s=google; h=date:from:to:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=0Xk3+PDTcjqsEatvwwc9xak6ajnNpxoeHtktQHxXuQ0=; b=mIel15PgM0e12QiJKwrF+WJDOUvE8p3Z3NXRxp8jBhi+VO/99XlD48XutCmbz/f9bc A+NNfCp4wpZ0Q6aB5E0mtWdB1aBULaSz6PHlo2xqiQqD1ehE7QGBb2/5MfqQ5ogIyrUo /04BBR1EGXE0UhX5xSm4/J3uanNBi0sXYLlZg=
X-Google-DKIM-Signature v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=0Xk3+PDTcjqsEatvwwc9xak6ajnNpxoeHtktQHxXuQ0=; b=qVxoLS+LYYhfCpqdruNoWycIV5wSJACeVrNczpQC2JYZWW9Z/arnUReFvHEGUqRD/i WrFd03652gt2zRy/DYGCJqFKccU+MzBFetHinzLQm1O+gZ22cUPROxvyvI2FseMyPGtB dRp9halvfnIKuRuu0rBHePiVV+l2JQqFLbeZre01j5n68FTMuxpgVGO8fW1RAeHO/5fb qfIKsZpPQRmhs+ywGvvYf1S6ujSCy2MYpcqA3WVQnAwm3YWDwI4Weelb2Fev7Iwi30lN TcnBBjTnBVvNR8clD73id4PQ2Uuujj+xWon3+jOBlyPG3p8AwUyrX87atlYk/yDMtcpr 0apg==
X-Gm-Message-State ANhLgQ2aYiFd1FPITV3uqTDqb/vwLx2TjESJ/q3P6lmCHtNiiMbuNveo NSKj7jkTWPsPWz2mF+5yWj39n0yVz0TJvw==
X-Google-Smtp-Source ADFU+vv2ZNJOqgyK0036yDguwDRo2B7UarGW+h4f8GgT5nrgJ8v9aSJoiQ9ODoKKtoJkSNd3wjVqmA==
X-Received by 2002:adf:f686:: with SMTP id v6mr5334293wrp.176.1583350158999; Wed, 04 Mar 2020 11:29:18 -0800 (PST)
Content-Disposition inline
In-Reply-To <20200304181824.GA394387@chrisdown.name>
X-detected-operating-system by eggs.gnu.org: Genre and OS details not recognized.
X-Received-From 2a00:1450:4864:20::430
X-BeenThere bug-bash@gnu.org
X-Mailman-Version 2.1.23
Precedence list
List-Id Bug reports for the GNU Bourne Again SHell <bug-bash.gnu.org>
List-Unsubscribe <https://lists.gnu.org/mailman/options/bug-bash>, <mailto:bug-bash-request@gnu.org?subject=unsubscribe>
List-Archive <https://lists.gnu.org/archive/html/bug-bash>
List-Post <mailto:bug-bash@gnu.org>
List-Help <mailto:bug-bash-request@gnu.org?subject=help>
List-Subscribe <https://lists.gnu.org/mailman/listinfo/bug-bash>, <mailto:bug-bash-request@gnu.org?subject=subscribe>
X-Mailman-Original-Message-ID <20200304192918.GB394387@chrisdown.name>
X-Mailman-Original-References <20200304181824.GA394387@chrisdown.name>
Xref csiph.com gnu.bash.bug:15988

Show key headers only | View raw


Ah, it's been a while since I did this and I forgot about the granularity of 
the devel branch :-)

There it bisects to 73a146bec7f75da9f78f6d54329c980b75a2318d ("commit 
bash-20130215 snapshot"). I'm pretty sure it's related to this change to add 
the signal handler inside initialize_shell_signals, which sets a new handler if 
SIGTERM isn't SIG_HARD_IGNORE.

If I read the code correctly, in that case we will resume due to SA_RESTART, 
but bubbling up readline() will now return 0, which will be passed to 
yy_readline_get(), which returns EOF if current_readline_line is 0, so the 
shell closes.

I'm not quite sure how best to handle this, maybe setting SIG_IGN as the 
default signal handler for interactive shells if there's nothing to inherit? 
This is one of those cases where SA_RESTART doesn't quite mimic SIG_IGN...

Back to gnu.bash.bug | Previous | Next | Find similar


Thread

Re: Change in SIGTERM behaviour in bash 4.3 when using readline Chris Down <chris@chrisdown.name> - 2020-03-04 19:29 +0000

csiph-web