use default prefix for ruby install if no user defined prefix is available

git-svn-id: svn://svn.oetiker.ch/rrdtool/branches/1.2@1515 a5681a0c-68f1-0310-ab6d-d61299d08faa

diff --git a/program/configure.ac b/program/configure.ac
index 434b5eed9ea5d3279b312faf06c0d6b378218338..d112874a962e5bdc183636f86ce967e5f6da2d7f 100644 (file)
--- a/program/configure.ac
+++ b/program/configure.ac
@@ -650,6 +650,8 @@ else
        fi                              
 fi
 
+rpref=$prefix
+test "$rpref" = "NONE" && rpref=$ac_default_prefix
 
 dnl pass additional ruby options when generating Makefile from Makefile.PL
 AC_ARG_ENABLE(ruby-site-install,
@@ -657,7 +659,7 @@ AC_ARG_ENABLE(ruby-site-install,
                          together with rrdtool in $prefix/lib/ruby. You have to
                           add $prefix/lib/ruby/$ruby_version/$sitearch to you $: variable
                           for ruby to find the RRD.so file.],
-[RUBY_MAKE_OPTIONS=],[RUBY_MAKE_OPTIONS="sitedir="'$(DESTDIR)'"$prefix/lib/ruby"])
+[RUBY_MAKE_OPTIONS=],[RUBY_MAKE_OPTIONS="sitedir="'$(DESTDIR)'"$rpref/lib/ruby"])
 
     
 AC_ARG_WITH(ruby-options,