NetBSD Problem Report #55454
From www@netbsd.org Fri Jul 3 17:59:48 2020
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Date: Fri, 3 Jul 2020 17:59:46 +0000 (UTC)
From: jnaman806@gmail.com
Reply-To: jnaman806@gmail.com
To: gnats-bugs@NetBSD.org
Subject: wredrawln() in libcurses does not follow the sensible behaviour
X-Send-Pr-Version: www-1.0
>Number: 55454
>Category: lib
>Synopsis: wredrawln() in libcurses does not follow the sensible behaviour
>Confidential: no
>Severity: serious
>Priority: medium
>Responsible: lib-bug-people
>State: closed
>Class: change-request
>Submitter-Id: net
>Arrival-Date: Fri Jul 03 18:00:00 +0000 2020
>Closed-Date: Wed Dec 15 06:45:46 +0000 2021
>Last-Modified: Wed Dec 15 06:45:46 +0000 2021
>Originator: Naman Jain
>Release: NetBSD 9.0
>Organization:
IIT Kanpur
>Environment:
NetBSD localhost 9.0 NetBSD 9.0 (GENERIC) #0: Fri Feb 14 00:06:28 UTC 2020 mkrepro@mkrepro.NetBSD.org:/usr/src/sys/arch/amd64/compile/GENERIC amd64
>Description:
The behavior in case (beg_line + num_lines) exceeds LINES(win->maxy)
in xcurses/wredrawln
(https://pubs.opengroup.org/onlinepubs/7908799/xcurses/redrawwin.html).
Though not explicitly mentioned, I the sensible behavior is to only
mark the lines after beg_line till the end of the window. (ncurses
does this)
Current NetBSD curses implementation marks last num_lines,
i.e. [LINES-num_lines, LINES) in this case.
This change also makes sense as for a window with win->maxy = 5,
beg_line = 2 and num_lines = 8 gives segmentation fault, using the
proposed behavior not only we be more reasonable but also protecting
against the seg fault.
>How-To-Repeat:
>Fix:
There is a quick short fix to this. Instead of setting
line = win->maxy - n;
we should set
n = win->maxy - line;
https://github.com/NetBSD/src/blob/trunk/lib/libcurses/touchwin.c#L180
>Release-Note:
>Audit-Trail:
From: "Valeriy E. Ushakov" <uwe@netbsd.org>
To: gnats-bugs@gnats.NetBSD.org
Cc:
Subject: PR/55454 CVS commit: src/lib/libcurses
Date: Fri, 3 Jul 2020 23:28:51 +0000
Module Name: src
Committed By: uwe
Date: Fri Jul 3 23:28:51 UTC 2020
Modified Files:
src/lib/libcurses: touchwin.c
Log Message:
wtouchln - verify/clip input parameters
From Naman Jain in PR lib/55454
To generate a diff of this commit:
cvs rdiff -u -r1.31 -r1.32 src/lib/libcurses/touchwin.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
State-Changed-From-To: open->closed
State-Changed-By: blymn@NetBSD.org
State-Changed-When: Wed, 15 Dec 2021 06:45:46 +0000
State-Changed-Why:
Uwe fixed this about 18 months ago.
>Unformatted:
(Contact us)
$NetBSD: query-full-pr,v 1.46 2020/01/03 16:35:01 leot Exp $
$NetBSD: gnats_config.sh,v 1.9 2014/08/02 14:16:04 spz Exp $
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