* configure.in: ignored working directory same as prefix value.

[ruby-core:54999] [Bug #8409]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47151 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Tue Aug 12 14:22:58 2014  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
+
+	* configure.in: ignored working directory same as prefix value.
+	  [ruby-core:54999] [Bug #8409]
+
 Tue Aug 12 13:34:25 2014  SHIBATA Hiroshi  <shibata.hiroshi@gmail.com>
 
 	* lib/fileutils.rb: enable to remove with non-owner directory.

configure.in

@@ -229,6 +229,10 @@ test -z "$CXX" || ac_cv_prog_CXX="$CXX"
 if test "$program_prefix" = NONE; then
   program_prefix=
 fi
+if test "$prefix" = `pwd`; then
+  echo "--prefix cannot be the current working directory."
+  exit 1;
+fi
 RUBY_BASE_NAME=`echo ruby | sed "$program_transform_name"`
 RUBYW_BASE_NAME=`echo rubyw | sed "$program_transform_name"`
 AC_SUBST(RUBY_BASE_NAME)