Use stub executables generated by RubyGems istead of original executables.

It resolved the conflict issues when invoking `gem i rdoc` and the binstub
issues with Bundler and Rails.

  [Bug #5060][ruby-core:38257][Fix GH-2023]

  * https://github.com/rubygems/rubygems/pull/2338
  * https://github.com/heroku/heroku-buildpack-ruby/issues/829

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65963 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 23 insertions, 8 deletions

diff --git a/bin/ri b/bin/ri
index 7fbed0c099..eaca302681 100755
--- a/bin/ri
+++ b/bin/ri
@@ -1,12 +1,27 @@
 #!/usr/bin/env ruby
+#
+# This file was generated by RubyGems.
+#
+# The application 'rdoc' is installed as part of a gem, and
+# this file is here to facilitate running it.
+#
 
-begin
-  gem 'rdoc'
-rescue NameError => e # --disable-gems
-  raise unless e.name == :gem
-rescue Gem::LoadError
-end
+require 'rubygems'
+
+version = ">= 0.a"
 
-require 'rdoc/ri/driver'
+if ARGV.first
+  str = ARGV.first
+  str = str.dup.force_encoding("BINARY") if str.respond_to? :force_encoding
+  if str =~ /\A_(.*)_\z/ and Gem::Version.correct?($1) then
+    version = $1
+    ARGV.shift
+  end
+end
 
-RDoc::RI::Driver.run ARGV
+if Gem.respond_to?(:activate_bin_path)
+load Gem.activate_bin_path('rdoc', 'ri', version)
+else
+gem "rdoc", version
+load Gem.bin_path("rdoc", "ri", version)
+end