Teach Rails apps to only load gems of the same Rails version they were generated with.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4109 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

railties/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Teach Rails apps to only load gems of the same Rails version they were generated with. [Nicholas Seckar]
+
 * Added expiration settings for JavaScript, CSS, HTML, and images to default lighttpd.conf [DHH]
 
 * Added gzip compression for JavaScript, CSS, and HTML to default lighttpd.conf [DHH]

railties/environments/boot.rb

@@ -13,7 +13,12 @@ if File.directory?("#{RAILS_ROOT}/vendor/rails")
   require "#{RAILS_ROOT}/vendor/rails/railties/lib/initializer"
 else
   require 'rubygems'
-  require 'initializer'
+  required_version = '<%= Rails::VERSION::STRING %>'
+  rails_gem = Gem.cache.search('rails', "=#{required_version}").first
+  unless rails_gem
+    STDERR.puts "Cannot find gem for Rails =#{required_version}. Install missing gem or change config/boot.rb."
+  end
+  require rails_gem.full_gem_path + '/lib/initializer'
 end
 
 Rails::Initializer.run(:set_load_path)

railties/lib/rails_generator/generators/applications/app/app_generator.rb

@@ -43,7 +43,7 @@ class AppGenerator < Rails::Generator::Base
       m.template "configs/apache.conf",   "public/.htaccess"
 
       # Environments
-      m.file "environments/boot.rb",        "config/boot.rb"
+      m.template "environments/boot.rb",    "config/boot.rb"
       m.file "environments/environment.rb", "config/environment.rb"
       m.file "environments/production.rb",  "config/environments/production.rb"
       m.file "environments/development.rb", "config/environments/development.rb"