rubygems.rb: use @gem_prelude_index

* lib/rubygems.rb (Gem.load_path_insert_index): search
  @gem_prelude_index first.
* lib/rubygems/test_case.rb (Gem::TestCase#setup): keep already
  expanded paths to prserve instance variables.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51104 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,11 @@
+Thu Jul  2 14:15:50 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/rubygems.rb (Gem.load_path_insert_index): search
+	  @gem_prelude_index first.
+
+	* lib/rubygems/test_case.rb (Gem::TestCase#setup): keep already
+	  expanded paths to prserve instance variables.
+
 Thu Jul  2 14:12:01 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ruby.c (process_options): also copy initial load path marks at

lib/rubygems.rb

@@ -577,6 +577,10 @@ module Gem
   # gem's paths are inserted before site lib directory by default.
 
   def self.load_path_insert_index
+    $LOAD_PATH.each_with_index do |path, i|
+      return i if path.instance_variable_defined?(:@gem_prelude_index)
+    end
+
     index = $LOAD_PATH.index RbConfig::CONFIG['sitelibdir']
 
     index

lib/rubygems/test_case.rb

@@ -269,7 +269,9 @@ class Gem::TestCase < MiniTest::Unit::TestCase
     Gem.ensure_gem_subdirectories @gemhome
 
     @orig_LOAD_PATH = $LOAD_PATH.dup
-    $LOAD_PATH.map! { |s| File.expand_path(s).untaint }
+    $LOAD_PATH.map! { |s|
+      (expand_path = File.expand_path(s)) == s ? s : expand_path.untaint
+    }
 
     Dir.chdir @tempdir