3 files changed, 16 insertions, 0 deletions
diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 0ae8cbdd93..945c2238df 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Raise an exception if both attr_protected and attr_accessible are declared.  #8507 [stellsmi]
+
 * SQLite, MySQL, PostgreSQL, Oracle: quote column names in column migration SQL statements.  #8466 [marclove, lorenjohnson]
 
 * Allow nil serialized attributes with a set class constraint.  #7293 [sandofsky]
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 36775d74b5..931afa61ba 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -2164,6 +2164,8 @@ module ActiveRecord #:nodoc:
           attributes.reject { |key, value| !self.class.accessible_attributes.include?(key.gsub(/\(.+/, "").intern) || attributes_protected_by_default.include?(key.gsub(/\(.+/, "")) }
         elsif self.class.accessible_attributes.nil?
           attributes.reject { |key, value| self.class.protected_attributes.include?(key.gsub(/\(.+/,"").intern) || attributes_protected_by_default.include?(key.gsub(/\(.+/, "")) }
+        else
+          raise "Declare either attr_protected or attr_accessible for #{self.class}, but not both."
         end
       end
 
diff --git a/activerecord/test/base_test.rb b/activerecord/test/base_test.rb
index 3171e75bac..d74a7b82b5 100755
--- a/activerecord/test/base_test.rb
+++ b/activerecord/test/base_test.rb
@@ -53,6 +53,12 @@ class Task < ActiveRecord::Base
   attr_protected :starting
 end
 
+class TopicWithProtectedContentAndAccessibleAuthorName < ActiveRecord::Base 
+  self.table_name = 'topics' 
+  attr_accessible :author_name
+  attr_protected  :content
+end
+
 class BasicsTest < Test::Unit::TestCase
   fixtures :topics, :companies, :developers, :projects, :computers, :accounts
 
@@ -771,6 +777,12 @@ class BasicsTest < Test::Unit::TestCase
     assert_raise(ActiveRecord::RecordInvalid) { reply.update_attributes!(:title => nil, :content => "Have a nice evening") }
   end
   
+  def test_mass_assignment_should_raise_exception_if_accessible_and_protected_attribute_writers_are_both_used
+    topic = TopicWithProtectedContentAndAccessibleAuthorName.new
+    assert_raises(RuntimeError) { topic.attributes = { "author_name" => "me" } }
+    assert_raises(RuntimeError) { topic.attributes = { "content" => "stuff" } }
+  end
+  
   def test_mass_assignment_protection
     firm = Firm.new
     firm.attributes = { "name" => "Next Angle", "rating" => 5 }