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

From: Dragan Simic <dsimic@manjaro.org>
To: Christoph Anton Mitterer <calestyo@scientia.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 01:29:41 +0200	[thread overview]
Message-ID: <6457310b8ca0e7d3b288a3bbbe264012@manjaro.org> (raw)
In-Reply-To: <ec43820562198de078db7df54d0338edf1f333ea.camel@scientia.org>

On 2023-10-12 01:16, Christoph Anton Mitterer wrote:
> On Thu, 2023-10-12 at 00:51 +0200, Dragan Simic wrote:
>> In general, not clearing the screen (i.e. "-X") is there so the
>> displayed contents is still visible in the terminal after exiting the
>> pager.  That wouldn't be the case if the screen was cleared, making
>> it
>> less usable for most users.
> 
> Well, I personally, also prefer it that way... but I'd also say that
> just like in the case of `S`, this is not really needed from the git
> side, but rather simply a user choice.

It's about providing a set of sane defaults for less(1), which other 
utilities also do, including dmesg, for example.  Of course, everyone 
can set $PAGER or $GIT_PAGER to fit their own prereferences.

> And since, if the output did not fit one one screen, the non-cleared
> remains may likely be chopped off,... one could argue that some users
> would actually prefer to have it cleared.

I'm not sure what do you mean by the non-cleared remains being chopped 
off...  Could you clarify that a bit, please?

As I already mentioned above, everyone is free to configure the pager 
behavior in any way they like.

>> Exiting if less contents than one full screen was displayed (i.e. "-
>> F")
>> is there to save people from the frustration of quitting a pager that
>> actually wasn't needed to be executed.
> 
> Same actually here, at least strictly speaking, ... though I (and
> probably everybody else?) would really hate it, if that was removed. ^^

I'm afraid that I don't understand very well are you complaining about 
the presence of "-F" or not?

> Anyway... that's no request from my side to change the default. I just
> wanted to know whether that don't-clear-the-screen part was the
> motivation for the `X`.

AFAIK, there should be no motivation other than not clearing the screen. 
  Other utilities that invoke the pager internally configure the default 
pager options in a very similar way.

> In case someone cares, I've asked less upstream whether there's a way
> to have VTE scrolling work with -X:
> https://github.com/gwsw/less/issues/445

Quite frankly, I can't stand scrolling in less(1) using the mouse wheel, 
but I do understand why some people like it.