1##rhinton: stolen from http://hg.savannah.gnu.org/hgweb/octave/rev/691545147aca
2dnl
3dnl If needed, define the m4_ifblank and m4_ifnblank macros from autoconf 2.64
4dnl This allows us to run with earlier Autoconfs as well.
5ifdef([m4_ifblank],[],[
6m4_define([m4_ifblank],
7[m4_if(m4_translit([[$1]],  [ ][        ][
8]), [], [$2], [$3])])])
9dnl
10ifdef([m4_ifnblank],[],[
11m4_define([m4_ifnblank],
12[m4_if(m4_translit([[$1]],  [ ][        ][
13]), [], [$3], [$2])])])
14dnl
15