# Pstricks bug: adding empty line messes pspicture

I have the following Example:

    \documentclass{article}
\usepackage{auto-pst-pdf}
\newcommand{\directionFieldOneTangent}[2]{
\pstVerb{%
/aaaaaaaaa #1 \space def
}%
\pscircle*[linecolor=red!60]( #1, #2){0.2}
}
\begin{document}
\begin{pspicture}(-2.7,-2.7)(2.7,2.7)
\directionFieldOneTangent{0}{0}

\directionFieldOneTangent{0}{0}
\end{pspicture}
\end{document}


Now the same example, with one empty line removed:

    \documentclass{article}
\usepackage{auto-pst-pdf}
\newcommand{\directionFieldOneTangent}[2]{
\pstVerb{%
/aaaaaaaaa #1 \space def
}%
\pscircle*[linecolor=red!60]( #1, #2){0.2}
}
\begin{document}
\begin{pspicture}(-2.7,-2.7)(2.7,2.7)
\directionFieldOneTangent{0}{0}
\directionFieldOneTangent{0}{0}
\end{pspicture}
\end{document}


The first file produces the output in the first pdf file: the two points do not coincide. Where should I report this bug, how can that be fixed, what is the issue?

-
It's not clear that it is necessarily a bug. A blank line is a \par command and the expected behaviour of \par is to inject vertical space. Perhaps a feature request that it be locally defined not to do that, but no package can make all incorrect input safe. –  David Carlisle Mar 12 at 17:46

1. As far as I know, any blank lines in pspicture will be ignored.
2. Any trailing whitespace after the opening curly brace of \newcommand{\<macroname>} must be removed by using %.
3. Any trailing whitespace after the closing curly brace of \pstVerb must be removed by using %.

So there is no bug because they are all well-known facts.

\newcommand{\directionFieldOneTangent}[2]{%<============= You have to kill the whitespace!
\pstVerb{%
/aaaaaaaaa #1 \space def
}%
\pscircle*[linecolor=red!60]( #1, #2){0.2}
}

-
it wouldn't hurt to add a % after 0.2} as well –  David Carlisle Mar 12 at 17:46
Thanks a lot for the answer! That resolves the issue. I follow all your % advice. As far as calling this behavior a bug... I like to stir up some controversy! When white space causes such drastic and difficult to predict changes, some controversial statements are deserved (If I were to design LaTeX/pstricks, I'd avoid such shady syntax behavior of the white space). –  user39417 Mar 13 at 4:06