problem with \eqn (PR#8322)

<snipped>

Definitely a problem in Rdconv.

E.g.,

$ cat foo.Rd 
\description{
  \eqn{{A}}{B}
}
hornik at mithrandir:~/tmp$ R-d CMD Rdconv -t latex foo.Rd | grep eqn
\eqn{{A}}{A}{{B}

shows what is going on.

There is a "work-around" - putting extra spaces between the two braces:

$ cat foo.Rd
\description{
   \eqn{ {A} }{B}
}

$R CMD Rdconv -t latex foo.Rd
\HeaderA{}{}{}
\begin{Description}\relax
\eqn{ {A} }{B}
\end{Description}


HT