why first line is missing using fancybox BVerbatim?

Question

Why is defining a new name for environment for a command produces different result than when using the environment directly without defining a name for it?

Here are 2 examples, one uses a name for the env. and one does it. The second one is missing the first line in the verbatim text. Same text is used in both examples.

Code is below:

\documentclass{article}
\usepackage{fancybox}

\newenvironment{myStuff}%
{\VerbatimEnvironment\begin{Sbox}\begin{BVerbatim}}%
{
\end{BVerbatim}\end{Sbox}\fbox{\TheSbox}
}    
\begin{document}        
\begin{myStuff}
line 1
line 2
line 3
\end{myStuff}
\end{document}

second example

\documentclass{article}
\usepackage{fancybox}

\begin{document}    

\begin{Sbox}\begin{BVerbatim}%
line 1
line 2
line 3
\end{BVerbatim}
\end{Sbox}\fbox{\TheSbox}
\end{document}

Texlive 2014

Answer 1

Your problem is that % after \begin{BVerbatim} in the second example. In the first example, the line \begin{myStuff} has a normal line ending (no %, so an end-of-line is seen), whereas as you've written it in the second example the % means that \begin{BVerbatim} 'runs on' into the line 1 line. I've not traced it through but I strongly suspect that \begin{BVerbatim} ignores the rest of the content of the 'current' line at the start of the environment. As a result, the % means that line 1 is ignored in the second case. Simply removing it solves the problem

\documentclass{article}
\usepackage{fancybox}

\begin{document}    

\begin{Sbox}\begin{BVerbatim}
line 1
line 2
line 3
\end{BVerbatim}
\end{Sbox}\fbox{\TheSbox}
\end{document}

Answer 2

Here is a solution with package fancyvrb:

\documentclass{article}
\usepackage{fancyvrb}    
\newenvironment{myStuff}
  {\VerbatimEnvironment
   \begin{SaveVerbatim}{VerbEnv}}
  {\end{SaveVerbatim}\fbox{\BUseVerbatim{VerbEnv}}}

\begin{document}        
\begin{myStuff}
line 1
line 2
line 3
\end{myStuff}
\end{document}

Answer 3

Here is a solution with the package verbatimbox.

\documentclass{article}
\usepackage{verbatimbox}
\begin{document}
\begin{verbbox}
line1
line2
line3
\end{verbbox}
\fbox{\theverbbox}
\end{document}