From e24d97c938c481450ed80ec83e5399595946c1ae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADt=20Ondruch?= <vondruch@redhat.com>
Date: Fri, 8 Feb 2013 22:48:41 +0100
Subject: [PATCH] Prevent duplicated paths when empty version string is
 configured.

---
 configure.ac     |  3 ++-
 loadpath.c       | 12 ++++++++++++
 tool/mkconfig.rb |  2 +-
 3 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index c42436c23d..d261ea57b5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -4196,7 +4196,8 @@ AS_CASE(["$ruby_version_dir_name"],
 ruby_version_dir=/'${ruby_version_dir_name}'
 
 if test -z "${ruby_version_dir_name}"; then
-    AC_MSG_ERROR([No ruby version, No place for bundled libraries])
+    unset ruby_version_dir
+    AC_DEFINE(RUBY_LIB_VERSION_BLANK, 1)
 fi
 
 rubylibdir='${rubylibprefix}'${ruby_version_dir}
diff --git a/loadpath.c b/loadpath.c
index 9160031..0d4d953 100644
--- a/loadpath.c
+++ b/loadpath.c
@@ -65,21 +65,33 @@ const char ruby_initial_load_paths[] =
     RUBY_SEARCH_PATH "\0"
 #endif
 #ifndef NO_RUBY_SITE_LIB
+#ifdef RUBY_LIB_VERSION_BLANK
+    RUBY_SITE_LIB "\0"
+#else
     RUBY_SITE_LIB2 "\0"
+#endif
 #ifdef RUBY_THINARCH
     RUBY_SITE_ARCH_LIB_FOR(RUBY_THINARCH) "\0"
 #endif
     RUBY_SITE_ARCH_LIB_FOR(RUBY_SITEARCH) "\0"
+#ifndef RUBY_LIB_VERSION_BLANK
     RUBY_SITE_LIB "\0"
 #endif
+#endif
 
 #ifndef NO_RUBY_VENDOR_LIB
+#ifdef RUBY_LIB_VERSION_BLANK
+    RUBY_VENDOR_LIB "\0"
+#else
     RUBY_VENDOR_LIB2 "\0"
+#endif
 #ifdef RUBY_THINARCH
     RUBY_VENDOR_ARCH_LIB_FOR(RUBY_THINARCH) "\0"
 #endif
     RUBY_VENDOR_ARCH_LIB_FOR(RUBY_SITEARCH) "\0"
+#ifndef RUBY_LIB_VERSION_BLANK
     RUBY_VENDOR_LIB "\0"
+#endif
 #endif
 
     RUBY_LIB "\0"
diff --git a/tool/mkconfig.rb b/tool/mkconfig.rb
index 07076d4..35e6c3c 100755
--- a/tool/mkconfig.rb
+++ b/tool/mkconfig.rb
@@ -115,7 +115,7 @@
     val = val.gsub(/\$(?:\$|\{?(\w+)\}?)/) {$1 ? "$(#{$1})" : $&}.dump
     case name
     when /^prefix$/
-      val = "(TOPDIR || DESTDIR + #{val})"
+      val = "(((TOPDIR && TOPDIR.empty?) ? nil : TOPDIR) || DESTDIR + #{val})"
     when /^ARCH_FLAG$/
       val = "arch_flag || #{val}" if universal
     when /^UNIVERSAL_ARCHNAMES$/