From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19996 invoked by alias); 11 Apr 2019 23:50:27 -0000 Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Received: (qmail 19589 invoked by uid 89); 11 Apr 2019 23:50:27 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-5.9 required=5.0 tests=AWL,BAYES_00,GIT_PATCH_2,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.1 spammy=H*f:sk:1555023, H*MI:sk:1555023, screen X-HELO: smtp-nf-201.his.com Received: from smtp-nf-201.his.com (HELO smtp-nf-201.his.com) (216.194.196.93) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 11 Apr 2019 23:50:25 +0000 Received: from cuda201.his.com (cuda201.his.com [216.194.196.22]) by smtp-nf-201.his.com (Postfix) with ESMTPS id 3748E60202 for ; Thu, 11 Apr 2019 19:50:23 -0400 (EDT) Received: from smtp-nf-202.his.com (smtp-nf-202.his.com [216.194.196.20]) by cuda201.his.com with ESMTP id T7kHrqp9YdurT3MW; Thu, 11 Apr 2019 19:50:22 -0400 (EDT) Received: from zproxy101.his.com (zproxy101.his.com [18.218.2.49]) by smtp-nf-202.his.com (Postfix) with ESMTPS id AC0B06013C; Thu, 11 Apr 2019 19:50:22 -0400 (EDT) Received: from localhost (localhost.localdomain [127.0.0.1]) by zproxy101.his.com (Postfix) with ESMTP id 81FB31786C8; Thu, 11 Apr 2019 19:50:22 -0400 (EDT) Received: from zproxy101.his.com ([127.0.0.1]) by localhost (zproxy101.his.com [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id ltLrkHMV0Xkk; Thu, 11 Apr 2019 19:50:22 -0400 (EDT) Received: from localhost (localhost.localdomain [127.0.0.1]) by zproxy101.his.com (Postfix) with ESMTP id 6ADF3179559; Thu, 11 Apr 2019 19:50:22 -0400 (EDT) Received: from zproxy101.his.com ([127.0.0.1]) by localhost (zproxy101.his.com [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id G5MyBkxFav2Y; Thu, 11 Apr 2019 19:50:22 -0400 (EDT) Received: from mb1.his.com (mb1.his.com [10.0.1.101]) by zproxy101.his.com (Postfix) with ESMTP id 4E9701786C8; Thu, 11 Apr 2019 19:50:22 -0400 (EDT) Date: Thu, 11 Apr 2019 23:50:00 -0000 From: Thomas Dickey To: Thomas Wolff Cc: cygwin Message-ID: <1750415886.9092694.1555026622274.JavaMail.zimbra@his.com> In-Reply-To: <276979345.9055306.1555023982346.JavaMail.zimbra@his.com> References: <1555023988.95356.ezmlm@cygwin.com> Subject: Re: *cause of* screen writing over restored buffer on detach/exit MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-SW-Source: 2019-04/txt/msg00092.txt.bz2 ----- Original Message ----- | From: "Thomas Dickey" | To: "Thomas Wolff" | Cc: "cygwin" | Sent: Thursday, April 11, 2019 7:06:22 PM | Subject: Re: *cause of* screen writing over restored buffer on detach/exit | ----- Original Message ----- || From: "Thomas Wolff" || To: "cygwin" || Sent: Wednesday, April 10, 2019 5:51:34 PM || Subject: Re: *cause of* screen writing over restored buffer on detach/exit | || Hi Thomas, || || Thomas Dickey wrote: ||> ----- Original Message ----- ||> | From: "Shaddy Baddah" ||> | To: "cygwin" ||> | Sent: Tuesday, April 9, 2019 11:18:19 PM ||> | Subject: Re: *cause of* screen writing over restored buffer on detach/exit ||> ||> | On 9/4/19 4:07 pm, Shaddy Baddah wrote: ||> |> ||> |> This helped with screen when using Putty to a Cygwin ssh session. For ||> |> some reason, it isn't helping for running screen locally in a mintty ||> |> session. And it's not mintty either, because I can ssh to a Debian ||> |> stretch server within mintty and I can use its screen without this ||> |> issue happening. Back to the drawing board for me. ||> | ||> | I understand the cause of the issue now, by capturing and comparing the ||> | escape characters used to control the terminal by screen on Cygwin and ||> | Debian. ||> | ||> | It is not so much the detach/exit is the issue, although the escape ||> | sequence for Cygwin includes a couple of extra xterm OSC Set Text ||> | Parameters -> Change Icon Name and Window Title outputs. I misdiagnosed ||> | this somehow. I can suppress the extra utmp error one of these OSC ||> | outputs, but it didn't/doesn't really make a difference. ||> | ||> | The issue is in the escape sequences sent to the terminal by Cygwin ||> | screen to switch to new windows buffer, as compared to Debian. ||> | ||> | Debian uses xterm sequence DECSET / ESC[?1049h in the switch to the new ||> | window. Cygwin uses the two sequences ESC7 / Save Cursor (DECSC) and ||> | ESC[?47l / DEC Private Mode Reset (DECRST) -> Use Normal Screen Buffer. ||> | ||> | ||> | The reason seems to be that the Debian screen package packages a custom ||> | /etc/screenrc that does not include this explicit term capability: ||> | ||> | ||> | # ||> | # Do not use xterms alternate window buffer. ||> | # This one would not add lines to the scrollback buffer. ||> | termcap xterm|xterms|xs ti=\E7\E[?47l ||> | terminfo xterm|xterms|xs ti=\E7\E[?47l ||> | ||> | ||> | ||> | If I comment these out, my screen issue is resolved. ||> | ||> | I'm not suggesting this is a problem with Cygwin screen... it is using ||> | the upstream settings. In fact, I am not confident to say where the ||> | fault lies. Perhaps screen is right to use these sequences, but the ||> | xterms used (putty and mintty) aren't doing the right thing? ||> ||> yes - that's one of a half-dozen cases where PuTTY has never matched xterm's ||> behavior. || I've tested the CSI?1049h and CSI?1049l pair on xterm, pterm, mintty and || see no difference. In what way would it not match? And what are the | | I mentioned it here: | | https://stackoverflow.com/questions/24613237/terminal-retains-bg-color-after-closing-vim-using-color-scheme-and-putty-256co/37869114#37869114 | || cases, do you have a list? | | no - I've a few notes which aren't incorporated into the terminal description | | https://invisible-island.net/ncurses/terminfo.src.html#tic-putty | | offhand, there's differences in wrapping, as well as how modifiers affect | cursor-keys. ...though now that I'm reading it, that one deals with color. (I do have a note about cursor-position problems with the interim 1047/1048, but suppose PuttY doesn't do that). -- Thomas E. Dickey http://invisible-island.net ftp://ftp.invisible-island.net -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple