On 2021-11-17 20:21 -0500, Thomas Dickey wrote:
> On Wed, Nov 17, 2021 at 05:16:52PM +0100, Sven Joachim wrote:
>> Control: reassign -1 ncurses-base 6.3-1
>>
>> On 2021-11-17 01:11 +0100, Josh Triplett wrote:
>>
>> > I just confirmed that upgrading *only* ncurses-base causes the issue to
>> > appear, and downgrading *only* ncurses-base causes the issue to
>> > disappear.
>>
>> Thanks, that makes sense. For me it is broken in bookworm already, but
>> others have seen it only after upgrading ncurses to 6.3-1. For the
>> reference, the relevant change in ncurses is this:
>>
>> ,----
>> | 20210925
>> | + add smglp and smgrp to vt420+lrmm, to provide useful data for the
>> | "tabs" +m option -TD
>> `----
>
> yes - I implemented left/right margins in xterm in 2012 (patch #279)
> (not quite as long ago as repeat_char).
>
> however, the left/right margin feature was present earlier:
>
> REV:1.730 terminfo.src 2019/05/18 18:58:45 tom
>
> add vt420 left/right margins for xterm-new
>
> +# Left/right margins are supported in xterm since patch #279 (2012/05/10)
> +vt420+lrmm|VT420 left/right margins,
> + mgc=\E[?69l, smglr=\E[?69h\E[%i%p1%d;%p2%ds,
>
>> The neovim developers have pushed a workaround:
>>
>> https://github.com/neovim/neovim/issues/16238
>
> ...which seems enough to fix their issue
> (they're checking if $XTERM_VERSION is set)
Aha, this also explains why I experienced the problem even with older
ncurses-base, I had started gnome-terminal from xterm!
> Since the feature was already present in a different form,
> it seems that neovim is the only widespread user of this.
Quite likely.
>> I am not quite sure what to do with this in ncurses. As long as the
>> problem only affects neovim and VTE based terminal emulators I am
>> inclined to ignore it, but if it turns out to be more widespread I could
>> back out the new feature, like I did in #933053.
>
> I don't see that it's necessary.
Yes, I think a versioned Breaks against neovim should be sufficient,
once a fixed neovim package is available.
> By the way, #933053 is kind of stale - likely there's no sufficiently
> old systems with broken vte libraries to appease.
Unfortunately there is at least one unfixed terminal emulator around,
#930037 and the corresponding upstream bug in mosh are still open.
Cheers,
Sven
