bug#59622: 29.0.50; [PATCH] Regression in Eshell's handling of escaped newlines

[Jim Porter]

On 12/5/2022 4:39 AM, Eli Zaretskii wrote:
> > +When you escape a character with @code{\} outside of quotes, the
> > +result is the literal character immediately following it, so
> > +@samp{\$10} means the literal string @code{$10}.  Inside of
> > +double quotes, the result is the literal character following it if
> > +that character is special, or the full @code{\@var{c}} sequence
> > +otherwise; inside double-quotes, @code{\}, @code{"}, and @code{$} are
> > +considered special.
>
> The last sentence is very unclear, please try saying what you need in a
> clearer way, and/or maybe add a couple of examples.

Ok, I expanded that part of the manual and added a few more examples. 
How does this look?

I also split the patch in two: the first patch for the 29 branch (which 
makes the least code changes I could manage), and the second as an 
additional small cleanup patch for master only.

29.1--0001-Treat-escaped-newlines-in-Eshell-as-the-empty-string.patch
Description: Text document

master--0002-Reorganize-the-conditionals-in-eshell-parse-backslas.patch
Description: Text document