\documentclass[a4paper]{article}

\usepackage{pgfplots}

\pgfplotsset{compat=1.5}

\begin{document}

\def\TEST#1{
	\begin{tikzpicture}
	%\tracingmacros=2 \tracingcommands=2
		\begin{axis}[
			title=should be red with ast marker and smooth,
			#1,
		]
		\begin{scope}[draw=red,mark=*,smooth,mark options={fill=blue}]
			\addplot[samples=3] {x^2};
			\legend{X}
		\end{scope}
		\end{axis}
	\end{tikzpicture}
}

\TEST{
	clip marker paths,
}

\TEST{
}
\end{document}

