Re: xterm-direct and zsh

[Oliver Kiddle <okiddle@xxxxxxxxxxx>]

"Aaron Jensen" wrote:
> I'm trying to use TERM=xterm-direct with zsh and finding that zle doesn't attempt to render things in 256 color, instead falling back to 8 color.

With TERM=xterm-direct, terminfo is reporting 16777216 (2^24) colours rather
than 256. So what's to say that a palette of specifically size 256 is
supported?

Are you able to point to some documentation for xterm-direct and what it
is supposed to achieve? It appears to exist to explicitly advertise
support for 24-bit colour in the terminal. Many terminals have support
but in the absence of a way to detect it, we've had to leave things up
to the user.

A side-effect of this is that it is no longer advertising support for a
256 color palette. It'd be good to know if that palette can be relied
upon when 2^24 are reported. Even if it can, I'm not sure whether that
is wise or is missing the point. In the past various smaller sizes were
also common (rxvt-unicode is still often built with 88).

> I found this patch, but it does not appear to be applied: https://inbox.vuxu.org/zsh-workers/20190207203257.7sfyvpooegdjgice@Daniels-MacBook-Air.local/
>
> Am I missing something or does zsh not properly support xterm-direct yet? I can't see where or why that patch never got merged.

It's a patch that needs significant review time. There's a lack of
documentation in ncurses so it would likely involve either guesswork
or trying to make sense of discussion from ncurses development. Then
understanding how things might react with other termcap/terminfo
implementations and terminal definitions given that it is potentially
adding assumptions to the code. The discussion with Sebastian somewhat
buried the original point of the change. It does 4 separate things
and change (b) is arguably pointless if the defacto standard works
everywhere. I think at the time, I only had time to take a glance once
that discussion was ended. I've added a note to my long TODO list and
copied in the author of the patch.

For the moment at least, I don't think any terminals are defaulting to
xterm-direct and most systems I use have no terminal definition for it.
So it requires people to be manually setting TERM to xterm-direct to
trip over the issues.

Oliver