diff -ur redmine-0.9.3/app/controllers/account_controller.rb redmine/app/controllers/account_controller.rb
--- redmine-0.9.3/app/controllers/account_controller.rb	2010-02-28 13:28:06.000000000 +0300
+++ redmine/app/controllers/account_controller.rb	2010-04-20 08:10:39.403029646 +0400
@@ -150,6 +150,7 @@
 
   
   def open_id_authenticate(openid_url)
+    cookies[:back_url] = { :value => CGI.unescape(params[:back_url].to_s) } unless params[:open_id_complete]
     authenticate_with_open_id(openid_url, :required => [:nickname, :fullname, :email], :return_to => signin_url) do |result, identity_url, registration|
       if result.successful?
         user = User.find_or_initialize_by_identity_url(identity_url)
diff -ur redmine-0.9.3/app/controllers/application_controller.rb redmine/app/controllers/application_controller.rb
--- redmine-0.9.3/app/controllers/application_controller.rb	2010-02-28 13:28:06.000000000 +0300
+++ redmine/app/controllers/application_controller.rb	2010-04-20 08:10:39.404033104 +0400
@@ -177,6 +177,10 @@
 
   def redirect_back_or_default(default)
     back_url = CGI.unescape(params[:back_url].to_s)
+    if back_url.blank?
+      back_url = cookies[:back_url]
+      cookies.delete :back_url
+    end
     if !back_url.blank?
       begin
         uri = URI.parse(back_url)
diff -ur redmine-0.9.3/test/functional/account_controller_test.rb redmine/test/functional/account_controller_test.rb
--- redmine-0.9.3/test/functional/account_controller_test.rb	2010-02-28 13:28:05.000000000 +0300
+++ redmine/test/functional/account_controller_test.rb	2010-04-20 08:49:39.123404798 +0400
@@ -67,6 +67,20 @@
     assert_redirected_to 'my/page'
   end
 
+  def test_login_should_redirect_to_back_url_param_with_openid
+    Setting.self_registration = '3'
+    Setting.openid = '1'
+    existing_user = User.new(:firstname => 'Cool',
+                             :lastname => 'User',
+                             :mail => 'user@somedomain.com',
+                             :identity_url => 'http://openid.example.com/good_user')
+    existing_user.login = 'cool_user'
+    assert existing_user.save!
+
+    post :login, :openid_url => existing_user.identity_url, :back_url => 'http%3A%2F%2Ftest.host%2Fissues%2Fshow%2F1'
+    assert_redirected_to '/issues/show/1'
+  end
+
   def test_login_with_openid_for_existing_non_active_user
     Setting.self_registration = '2'
     Setting.openid = '1'