Re: [possible patch] Remove the '\\[0pt]' string from the last line of a verse block in LaTeX export

[Juan Manuel Macías]

Ihor Radchenko writes:

> Juan Manuel Macías <maciaschain@posteo.net> writes:
>
>>> In such scenario, we may technically violate what users ask us to do:
>>>
>>> #+begin_verse
>>> I really want newline here\\
>>> #+end_verse
>>
>> I'm not sure if users asked for that specifically.
>> ...
>> This does not:
>>
>>  #+begin_verse
>>  I really want newline here\\
>>  #+end_verse
>
> I am not sure.
> What about
>
> #+begin_verse
> I really want newline here\\
> #+end_verse
>
> This must not be indented.

If I'm not mistaken, in TeX '\\' can only be used in horizontal mode:
that is, within a paragraph. At the end of an environment like verse
(\end{verse}) you are forced to enter vertical mode, and a new paragraph
starts. Doing something like this, for example, adds a new paragraph
after the environment:

\documentclass{article}
\usepackage{lipsum}
\begin{document}
\begin{verse}
  Lorem ipsum dolor\\
\end{verse}
\lipsum[1]
\end{document}

Even this one produces the same result:

\documentclass{article}
\usepackage{lipsum}
\begin{document}
\begin{verse}
  Lorem ipsum dolor\\
\end{verse}\lipsum[1]
\end{document}

If one wants, for example, that after a verse environment there is no
vertical space or indentation, the only way to do it is by modifying, globally 
or
locally (with another environment) the space after the environment and
adding a \noindent to the following paragraph:

\documentclass{article}
\usepackage{lipsum}
\setlength\partopsep{-\topsep}\addtolength\partopsep{0pt}
\begin{document}
\begin{verse}
  Lorem ipsum dolor\\
\end{verse}
\noindent\lipsum[1]
\end{document}

(taking into account that within the verse environment there is also a
left indentation that would also have to be modified).

Therefore, I think that whether or not a verse environment ends with \\ is
irrelevant to LaTeX. The problem is that when it ends with \\[0pt], for
some reason that escapes me, the space after the environment is altered.

Best regards,

Juan Manuel