Cookie session store: empty and unchanged sessions don't write a cookie.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6226 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 19 insertions, 2 deletions

diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index 20258b536e..396fa98a76 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Cookie session store: empty and unchanged sessions don't write a cookie.  [Jeremy Kemper]
+
 * Added helper(:all) as a way to include all helpers from app/helpers/**/*.rb in ApplicationController [DHH]
 
 * Integration tests: introduce methods for other HTTP methods.  #6353 [caboose]
diff --git a/actionpack/lib/action_controller/session/cookie_store.rb b/actionpack/lib/action_controller/session/cookie_store.rb
index 8763a4933a..1754eb34b1 100644
--- a/actionpack/lib/action_controller/session/cookie_store.rb
+++ b/actionpack/lib/action_controller/session/cookie_store.rb
@@ -65,7 +65,7 @@ class CGI::Session::CookieStore
 
   # Write the session data cookie if it was loaded and has changed.
   def close
-    if defined? @data
+    if defined?(@data) && !@data.blank?
       updated = marshal(@data)
       raise CookieOverflow if updated.size > MAX
       write_cookie('value' => updated) unless updated == @original
@@ -74,6 +74,7 @@ class CGI::Session::CookieStore
 
   # Delete the session data by setting an expired cookie with no data.
   def delete
+    @data = nil
     write_cookie('value' => '', 'expires' => 1.year.ago)
   end
 
diff --git a/actionpack/test/controller/session/cookie_store_test.rb b/actionpack/test/controller/session/cookie_store_test.rb
index 7a12fb4650..353785825b 100755
--- a/actionpack/test/controller/session/cookie_store_test.rb
+++ b/actionpack/test/controller/session/cookie_store_test.rb
@@ -68,11 +68,20 @@ class CookieStoreTest < Test::Unit::TestCase
     end
   end
 
+  def test_close_doesnt_write_cookie_if_data_is_blank
+    new_session do |session|
+      assert_nil session.cgi.output_cookies, session.cgi.output_cookies.inspect
+      session.close
+      assert_nil session.cgi.output_cookies, session.cgi.output_cookies.inspect
+    end
+  end
+
   def test_close_doesnt_write_cookie_if_data_is_unchanged
     set_cookie! Cookies::TYPICAL.first
     new_session do |session|
       assert_nil session.cgi.output_cookies, session.cgi.output_cookies.inspect
       session['user_id'] = session['user_id']
+      session.close
       assert_nil session.cgi.output_cookies, session.cgi.output_cookies.inspect
     end
   end
@@ -91,7 +100,7 @@ class CookieStoreTest < Test::Unit::TestCase
     end
   end
 
-  def test_delete_writes_expired_empty_cookie
+  def test_delete_writes_expired_empty_cookie_and_sets_data_to_nil
     set_cookie! Cookies::TYPICAL.first
     new_session do |session|
       assert_nil session.cgi.output_cookies, session.cgi.output_cookies.inspect
@@ -100,6 +109,11 @@ class CookieStoreTest < Test::Unit::TestCase
       cookie = session.cgi.output_cookies.first
       assert_equal ['_myapp_session', [], 1.year.ago.to_date],
                    [cookie.name, cookie.value, cookie.expires.to_date]
+
+      # @data is set to nil so #close doesn't send another cookie.
+      session.close
+      assert_equal ['_myapp_session', [], 1.year.ago.to_date],
+                   [cookie.name, cookie.value, cookie.expires.to_date]
     end
   end