Re: [PATCH] Update Alacritty terminfo

[Christian Dürr]

On Sun, Jan 12, 2020, at 12:38, Thomas Dickey wrote:
> On Tue, Dec 31, 2019 at 05:00:04PM +0100, Christian Dürr wrote:
> > This updates the Alacritty terminfo to the latest revision available in its
> > repository.
>
> I've been busy, but took a quick look last night.
>
> Offhand (I haven't investigated the key-modifiers),
> the only change needed appears to be the overlooked "ech" feature.

I'd assume by this you mean that the `ech` feature should be removed, since
Alacritty does not support it?

I've checked `vttest` and it performed exactly as XTerm, with the small
exception that the window is not automatically resized. The lack of automatic
resizing can lead to issue swith `vttest` though, which means `Delete
Characters` suddenly looks like `ABAAAAAAAA...` instead of `AB`, since the
characters "outside" the expected window size aren't removed.

Since it resizes half way through the test, that makes it quite difficult to
verify though. I had to run the test twice, making sure the window had the exact
right size for each part of the test before starting either of them.

I'd assume that it's not a requirement for `vttest` to be able to resize the
window by itself, right? Since Alacritty's results are identical with Termite
when the awkward resizing is ignored and it's just all run at big terminal
widths.

Also just to clarify, I ran the test `8` of `vttest`.

> > Since there have been some changes made to the xterm base, it does not use 
> > the
> > xterm terminfo anymore. However it would probably be possible to extract 
> > some of
> > the things if it's desirable to minimize size.
> >
> > I've also taken the liberty to update some of the notes made, that I do not
> > believe are accurate anymore. The multiple modifiers was actively patched. I
>
> I'll have to retest that (but I'll retest from a package, _not_
> from development source).  The only package that I'm aware of is
> on Arch Linux; last week I worked around one of those periodic
> issues with Arch where their upgrade needed a lot of tweaks to go.

I've given my best effort to evaluate these myself, but some extra testing and
feedback would be much appreciated.

Unfortunately it's true that Alacritty is not packaged on Fedora/Debian/Ubuntu,
which I'd assume would be usual platforms to test on. There's a PPA kindly
provided by the Pop!_OS developers, but unfortunately that's not an official
package either.

Besides source-based distros like Gentoo and more niche options like Void or
Mageia, the only official package I'm aware of is for openSUSE. However even
there Leap unfortunately only has an extremely outdated version (0.1.0) and the
only useful version for testing would be openSUSE Tumbleweed (0.4.0).

> > wasn't aware of issues with cursor position after leaving the alt screen, 
> > but
> > comparing it to XTerm does not show any difference to me.
> >
> > If there's any inaccurate statements or improvements to be made, please let 
> > me
> > know and I can fix things upstream in Alacritty.
>
> The changes to the comments aren't useful/accurate.  The alacritty terminfo
> entry isn't a _derived_ work since it doesn't introduce new/original features.
>
> (ncurses terminal database will use building-blocks to make the relationships
> clear, whether or not your source uses those).

I've chosen the word 'derived' since we have started out with XTerm and our
terminfo database then slowly evolved into what it is today. If this is
misleading and or confusing, changing the wording shouldn't be an issue, unless
this is about more than just the wording itself?

Kind regards,

Christian Duerr