Re: quite annoying bug in ncurses

[Thomas Dickey]

On Fri, 2 Apr 2004, Per [utf-8] �^Xyvind Karlsen wrote:

> Hi, we're trying to figure out quite an annoying bug in ncurses which affects
> irssi, mutt, nano etc.
>
> Problem is explained here:
> http://qa.mandrakesoft.com/show_bug.cgi?id=7209

I'm not familiar enough with irssi to exercise it much.  The code uses
(supposedly termcap) the terminfo interface.  The recent bug-fix would
be relevant on PowerPC, but not on Intel hardware.  Since irssi doesn't
use any other part of ncurses than these functions:

setupterm
tigetflag
tigetnum
tigetstr
tparm
tputs

it should be sufficient to trace (ltrace for instance) and see the
values returned by these calls, to ensure that you have the fix for
tigetflag (it should not return a 255 or 254).

nano and mutt use ncurses, and their approach to scrolling is entirely
different.  Actually running nano, I don't see it _scrolling_ per se - it
jumps by half-screens.  That's nano 1.2.3.  nm tells me that it's not
ncurses that does that - nano doesn't use any of the applicable calls
for scrolling.  Mutt appears to work correctly as well.

The bug report doesn't go into much detail other than to say that there's
a problem which looks like the application is setting the scrolling
margins incorrectly.  That's a common programming error which isn't
related to ncurses.

(If the report mentioned only gnome-terminal, I would simply ignore it,
since it appears that every time someone mentions gnome-terminal, it is
to describe one of its bugs).

-- 
Thomas E. Dickey
http://invisible-island.net
ftp://invisible-island.net