make install DESTIR=... vs. prefix=... (gnuplot)

[Mojca Miklavec]

Dear Macports gurus,

Some time ago there has been a bug report about some gnuplot files not
ending up in DESTROOT. See
    https://trac.macports.org/ticket/32872

With some help I have diagnosed the problem and found the solution,
however a friend (heavy linux geek whose opinion I highly respect)
claims that
    make install prefix=/path/to/that/weird/macports/destroot
(which is what macports does for gnuplot) is the wrong way of
installing and that one should use
    make install DESTDIR=/path/to/that/weird/macports/destroot
instead. Using DESTDIR= instead of prefix= indeed solves the problem
with files ending up in
    /opt/local/share/texmf/tex/latex/gnuplot/
without being destrooted first.

But I would like to hear the perspective/opinions from MacPorts
developers first.

Thank you,
    Mojca

PS: The solution is adding
  else
    TEXDIR='${prefix}'"$TEXDIR"
to configure[.in] (plus adding proper quoting in some places), so that
"make install prefix=..." is able to put
/path/to/that/weird/macports/destroot in front of
    /opt/local/share/texmf/tex/latex/gnuplot