The freeze_gems Rake task accepts the VERSION environment variable to decide which version of Rails to pull into vendor/rails.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2838 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 23 insertions, 6 deletions

diff --git a/railties/CHANGELOG b/railties/CHANGELOG
index 4fa88d630d..c6914af35c 100644
--- a/railties/CHANGELOG
+++ b/railties/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* The freeze_gems Rake task accepts the VERSION environment variable to decide which version of Rails to pull into vendor/rails.  [Chad Fowler, Jeremy Kemper]
+
 * Removed script.aculo.us.js, builder.js and slider.js (preperation for move of scriptaculous extensions to plugins, core scriptaculous will remain in Railties) [Thomas Fuchs]
 
 * The freeze_edge Rake task does smarter svn detection and can export a specific revision by passing the REVISION environment variable.  For example: rake freeze_edge REVISION=1234.  #2663 [Rick Olson]
diff --git a/railties/lib/tasks/framework.rake b/railties/lib/tasks/framework.rake
index 727a186fe1..51c277c641 100644
--- a/railties/lib/tasks/framework.rake
+++ b/railties/lib/tasks/framework.rake
@@ -2,13 +2,28 @@ desc "Lock this application to the current gems (by unpacking them into vendor/r
 task :freeze_gems do
   rm_rf   "vendor/rails"
   mkdir_p "vendor/rails"
-  
-  for gem in %w( actionpack activerecord actionmailer activesupport actionwebservice )
-    system "cd vendor/rails; gem unpack #{gem}"
-    FileUtils.mv(Dir.glob("vendor/rails/#{gem}*").first, "vendor/rails/#{gem}")
+
+  deps = %w( actionpack activerecord actionmailer activesupport actionwebservice )
+  if version = ENV['VERSION']
+    puts "Freezing to the gems for Rails #{version}"
+    require 'rubygems'
+    if rails = Gem.cache.search('rails').find { |g| g.version.to_s == version }
+      rails.dependencies.select { |g| deps.include? g.name }.each do |g|
+        system "cd vendor/rails; gem unpack -v '#{g.version_requirements}' #{g.name}; mv #{g.name}* #{g.name}"
+      end
+      system "cd vendor/rails; gem unpack -v '= #{version}' rails"
+    else
+      puts "No rails gem version #{version} is installed.  Do 'gem list rails' to see which versions you have available."
+      exit
+    end
+  else
+    puts "Freezing to your latest Rails gems"
+    for gem in deps
+      system "cd vendor/rails; gem unpack #{gem}"
+      FileUtils.mv(Dir.glob("vendor/rails/#{gem}*").first, "vendor/rails/#{gem}")
+    end
+    system "cd vendor/rails; gem unpack rails"
   end
-  
-  system "cd vendor/rails; gem unpack rails"
   FileUtils.mv(Dir.glob("vendor/rails/rails*").first, "vendor/rails/railties")
 end