bug#69555: 30.0.50; shr - Preserve indentation when shr-fill-text is nil

[Eli Zaretskii <eliz@gnu.org>]

> From: Kévin Le Gouguec <kevin.legouguec@gmail.com>
> Cc: 69555@debbugs.gnu.org,  rahguzar@zohomail.eu
> Date: Tue, 05 Mar 2024 20:22:52 +0100
> 
> Eli Zaretskii <eliz@gnu.org> writes:
> 
> > Also, please time the code on some substantially large body of text,
> > with and without shr-fill-text, and compare that with the current
> > version.  I think performance is an important aspect of any change in
> > this area.
> 
> Can do; would "(elisp) Profiling" be the starting point?

I think benchmark-run is a better starting point.

> (Also wondering if we have any "standard" or preferred HTML documents or
> websites to throw at shr.el for benchmarking purposes; if not, I guess
> I'll peruse <https://en.wikipedia.org/wiki/Special:LongPages> 🤔)

Actually, something with a lot of text in large paragraphs, sometimes
indented, would be better.  Those Wikipedia pages are basically long
lists, but there's not much opportunity there to perform filling and
indentation of large amounts of text, which is what is sought here.
Here's one possible candidate:

  https://debbugs.gnu.org/Developer.html