From e3898491f2960890d866bfe08e221a4cb52cfccc Mon Sep 17 00:00:00 2001
From: Michael Koziarski <michael@koziarski.com>
Date: Thu, 19 Jan 2006 08:47:18 +0000
Subject: [PATCH] make error_messages_for return "" for nil objects

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3438 5ecf4fe2-1ee6-0310-87b1-e25e094e27de
---
 actionpack/CHANGELOG                                       | 2 ++
 actionpack/lib/action_view/helpers/active_record_helper.rb | 4 +++-
 actionpack/test/template/active_record_helper_test.rb      | 4 ++++
 3 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index 4cdd6c555f..ec0216f565 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* allow nil objects for error_messages_for [Michael Koziarski]
+
 * Refactor human_size to exclude decimal place if it is zero. [Marcel Molina Jr.]
 
 * Update to Prototype 1.5.0_pre0 [Sam Stephenson]
diff --git a/actionpack/lib/action_view/helpers/active_record_helper.rb b/actionpack/lib/action_view/helpers/active_record_helper.rb
index 41d63fbc9a..dccae1db41 100644
--- a/actionpack/lib/action_view/helpers/active_record_helper.rb
+++ b/actionpack/lib/action_view/helpers/active_record_helper.rb
@@ -103,7 +103,7 @@ module ActionView
       def error_messages_for(object_name, options = {})
         options = options.symbolize_keys
         object = instance_variable_get("@#{object_name}")
-        unless object.errors.empty?
+        if object && !object.errors.empty?
           content_tag("div",
             content_tag(
               options[:header_tag] || "h2",
@@ -113,6 +113,8 @@ module ActionView
             content_tag("ul", object.errors.full_messages.collect { |msg| content_tag("li", msg) }),
             "id" => options[:id] || "errorExplanation", "class" => options[:class] || "errorExplanation"
           )
+        else
+          ""
         end
       end
 
diff --git a/actionpack/test/template/active_record_helper_test.rb b/actionpack/test/template/active_record_helper_test.rb
index acff1b5e40..e153e630ab 100644
--- a/actionpack/test/template/active_record_helper_test.rb
+++ b/actionpack/test/template/active_record_helper_test.rb
@@ -119,6 +119,10 @@ class ActiveRecordHelperTest < Test::Unit::TestCase
     assert_dom_equal %(<div class="errorExplanation" id="errorExplanation"><h2>1 error prohibited this post from being saved</h2><p>There were problems with the following fields:</p><ul><li>Author name can't be empty</li></ul></div>), error_messages_for("post")
     assert_equal %(<div class="errorDeathByClass" id="errorDeathById"><h1>1 error prohibited this post from being saved</h1><p>There were problems with the following fields:</p><ul><li>Author name can't be empty</li></ul></div>), error_messages_for("post", :class => "errorDeathByClass", :id => "errorDeathById", :header_tag => "h1")
   end
+  
+  def test_error_messages_for_handles_nil
+    assert_equal "", error_messages_for("notthere")
+  end
 
   def test_form_with_string_multipart
     assert_dom_equal(