Re: why does git set X in LESS env var?

From: Christoph Anton Mitterer <calestyo@scientia.org>
To: Dragan Simic <dsimic@manjaro.org>
Cc: Junio C Hamano <gitster@pobox.com>, git@vger.kernel.org
Subject: Re: why does git set X in LESS env var?
Date: Thu, 12 Oct 2023 02:22:49 +0200	[thread overview]
Message-ID: <8f3bec2752f4c2d3ebdd29d20910a4a94f75f608.camel@scientia.org> (raw)
In-Reply-To: <ace230a469fabbbbceb38cc884a40b4c@manjaro.org>

On Thu, 2023-10-12 at 02:06 +0200, Dragan Simic wrote:
> There's also scrollback in the terminal, which can be used to show
> more 
> of the contents that was displayed before exiting the pager.

Sure.

> > Everything that would have come after that is of course not
> > visible.
> > The place where I exited may be some "well defined" border, like
> > the
> > end of a commit... or anywhere it the middle of a patch (making the
> > left over remains on the terminal perhaps even ambiguous).
> 
> If you didn't select some line or page to be displayed, by scrolling 
> within the pager, it obviously isn't going to be displayed, which is
> the 
> whole point of using a pager instead of "spitting" the whole contents
> out at once.

It's also clear that it's one point of a pager :-)

But that doesn't change that it's rather a user decision, whether or
not it makes sense to leave that, what's already been shown by the
pager, on the terminal after exiting the pager or not.

I don't think people always select the lines in the pager to some
reasonable border (e.g. end of a commit, end of a hunk, whatever).
So it's likely that after leaving the pager, the terminal's scrollback
buffer will contain something that is not complete and may thus be
ambiguous.

> 
> That sounds like some issue with your terminal or terminal emulator, 
> which should be debugged and fixed separately.  Such misbehavior
> isn't 
> supposed to happen at all.

Are you sure about that?

Well it happens at least in gnome-terminal, xterm and (KDE) konsole.

> I see.  Actually, removing "-S" was a good decision, IMHO, because 
> chopping long lines isn't something that a sane set of defaults
> should 
> do.  Many users would probably be confused with the need to use the 
> right arrow to see long lines in their entirety.

Sure.

And having -F is IMO a good default (that virtually everyone would
want), too.

With respect to -X, I'm less sure whether it's that clear.

Cheers,
Chris.