unable to run ./prepare on branch 4.6

[Mojca M. <moj...@gm...>]

Dear gnuplotters,

I'm still trying to figure out what exactly goes wrong with AquaTerm's
clipping code (https://sourceforge.net/p/gnuplot/bugs/1188/).

a) trunk version of gnuplot, aquaterm.trm version A: works
b) trunk version of gnuplot, aquaterm.trm version B: doesn't work
c) gnuplot 4.6, aquaterm.trm version A: doesn't work
d) gnuplot 4.6, aquaterm.trm version B: doesn't work

I'm totally confused about (c) - I thought it would work, but I have
another request first. I tried to run ./prepare on branch 4.6 in order
to exclude the (unlikely) option of autotools having unexpected
behaviour (as it already turned out in past that a buggy version of
autotools lead to weird problems with Booleans on Mac).

The problem is that I'm unable to compile the 4.6 branch:

> ./prepare
aclocal: warning: autoconf input should be named 'configure.ac', not
'configure.in'
configure.in:12: error: 'AM_CONFIG_HEADER': this macro is obsolete.
    You should use the 'AC_CONFIG_HEADERS' macro instead.
/opt/local/share/aclocal-1.13/obsolete-err.m4:12: AM_CONFIG_HEADER is
expanded from...
configure.in:12: the top level
autom4te: /opt/local/bin/gm4 failed with exit status: 1
aclocal: error: echo failed with exit status: 1

Some part of the preparation process failed.
Please refer to INSTALL for details.

May I please request patching autoconf/automake files in that branch
to simplify testing?

Thank you,
Mojca