How to preserve the same parskip in minipage

Question

I have following structure:

\begin{document}

Paragraph1.
Paragraph2.

\begin{minipage}
Some paragraph1.
Some paragraph2.
\end{minipage}

\end{document}

How can I make the same spacing between paraghs in minipage section as in plain paragraphs? Would like to make it as macros, in order not to repeat it many times, but this failed:

\let\currentparskip\parskip
\newenvironment{minipage_parskip}{
  \begin{minipage}{\textwidth}{
    \setlength{\parskip}{\currentparskip}
  }
}{
  \end{minipage}
}

Answer 1

\parskip is the name of the length parameter that contains the current value of the parskip; so \let\currentparskip=\parskip and \setlength{\parskip}{\currentparskip} is equivalent to \setlength{\parskip}{\parskip} and inside a minipage does nothing, as the value of \parskip is already zero.

\newlength{\currentparskip}
\newenvironment{minipageparskip}
  {\setlength{\currentparskip}{\parskip}% save the value
   \begin{minipage}{\textwidth}% open the minipage
   \setlength{\parskip}{\currentparskip}% restore the value
  }
  {\end{minipage}}

While an underscore in the name of an environment is not forbidden, it's better not to use it, as some packages do change its meaning and may break your environment.

Answer 2

Both \parbox and \begin{minipage} temporarily reset \parindent=0pt and \parskip=0pt (and a few other parameters), which can be a nuisance.

Fortunately, \begin{minipage} also executes the \@minipagerestore macro after this, which is a hook to allow a LaTeX style to override these defaults. (See the ltboxes section in "texdoc source2e".)

So just try something like

\usepackage{parskip}
\setlength{\parskip}{\medskipamount}
\newcommand{\@minipagerestore}{\setlength{\parskip}{\medskipamount}}

in your style or class file.

Changing the behaviour of the existing "minipage" environment has the advantage that this will automatically affect the many other environments that use minipage internally (such as "columns" in beamer).