# Why does mdframed “hidealllines” actually show all lines?

I'm trying to use the hidealllines key for mdframed, but it's not working, either as a local argument or in an \mdfsetup. It works when I set all the topline=false, etc., but not when I just use hidealllines—and, furthermore, hidealllines seems to undo the hiding if each line is explicityly hidden!

# MWE

\documentclass{article}

\usepackage[tikz]{mdframed}

\begin{document}

\mdfsetup{backgroundcolor=blue!10}

% all lines, as expected
\begin{mdframed}
Text.
\end{mdframed}

% all lines (huh?)
\begin{mdframed}[hidealllines]
Text.
\end{mdframed}

% no lines, as expected
\begin{mdframed}[topline=false,rightline=false,bottomline=false,leftline=false]
Text.
\end{mdframed}

% all lines (huh??!)
\begin{mdframed}[topline=false,rightline=false,bottomline=false,leftline=false,hidealllines]
Text.
\end{mdframed}

\end{document}

Although this isn't stated in the documentation, you have to explicitly set hidealllines=true, not simply hidealllines. (The documentation examples do use this, but the key description just says that "you can use the short form hidealllines.")

A corrected MWE:

\documentclass{article}

\usepackage{xcolor}
\usepackage{mdframed} % works with tikz/pstricks as well

\begin{document}

\mdfsetup{backgroundcolor=blue!10}

\begin{mdframed}[hidealllines]
Lines are not hidden.
\end{mdframed}

\begin{mdframed}[hidealllines=true]
Lines are hidden.
\end{mdframed}

\end{document}