Fix that ActiveRecord would create attribute methods and override custom attribute getters if the method is also defined in Kernel.methods. [Rick]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@7749 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

4 files changed, 54 insertions, 15 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 179998b6a7..9410de60c2 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Fix that ActiveRecord would create attribute methods and override custom attribute getters if the method is also defined in Kernel.methods. [Rick]
+
 * Don't call attr_readonly on polymorphic belongs_to associations, in case it matches the name of some other non-ActiveRecord class/module.  [Rick]
 
 * Try loading activerecord-<adaptername>-adapter gem before trying a plain require so you can use custom gems for the bundled adapters. Also stops gems from requiring an adapter from an old Active Record gem.  [Jeremy Kemper, Derrick Spell]
@@ -45,8 +47,7 @@
 
 * Deprecation: remove deprecated threaded_connections methods. Use allow_concurrency instead.  [Jeremy Kemper]
 
-* Associations macros accept extension blocks alongside modules.  #9346 [Josh
-Peek]
+* Associations macros accept extension blocks alongside modules.  #9346 [Josh Peek]
 
 * Speed up and simplify query caching.  [Jeremy Kemper]
 
diff --git a/activerecord/lib/active_record/attribute_methods.rb b/activerecord/lib/active_record/attribute_methods.rb
index 695e9caae3..b17f72741a 100644
--- a/activerecord/lib/active_record/attribute_methods.rb
+++ b/activerecord/lib/active_record/attribute_methods.rb
@@ -76,20 +76,18 @@ module ActiveRecord
         end
       end
 
+      # Check to see if the method is defined in the model or any of it's subclasses that also derive from ActiveRecord.
+      # Raise DangerousAttributeError if the method is defined by ActiveRecord though.
       def instance_method_already_implemented?(method_name)
-        if method_defined?(method_name) || private_method_defined?(method_name) || protected_method_defined?(method_name)
-          # method is defined but maybe its a simple Kernel:: method which we could simply override
-          @@_overrideable_kernel_methods ||= Set.new(Kernel.methods)
-          !@@_overrideable_kernel_methods.include?(method_name)
-        else
-          false
-        end
+        return true if method_name =~ /^id(=$|\?$|$)/
+        @_defined_class_methods         ||= Set.new(ancestors.first(ancestors.index(ActiveRecord::Base)).collect! { |m| m.public_instance_methods(false) | m.private_instance_methods(false) | m.protected_instance_methods(false) }.flatten)
+        @@_defined_activerecord_methods ||= Set.new(ActiveRecord::Base.public_instance_methods(false) | ActiveRecord::Base.private_instance_methods(false) | ActiveRecord::Base.protected_instance_methods(false))
+        raise DangerousAttributeError, "#{method_name} is defined by ActiveRecord" if @@_defined_activerecord_methods.include?(method_name)
+        @_defined_class_methods.include?(method_name)
       end
       
       alias :define_read_methods :define_attribute_methods
 
-
-
       private
         # Suffixes a, ?, c become regexp /(a|\?|c)$/
         def rebuild_attribute_method_regexp
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index df15457a9a..5e1185065e 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -29,11 +29,14 @@ module ActiveRecord #:nodoc:
   end
   class StaleObjectError < ActiveRecordError #:nodoc:
   end
-  class ConfigurationError < StandardError #:nodoc:
+  class ConfigurationError < ActiveRecordError #:nodoc:
   end
-  class ReadOnlyRecord < StandardError #:nodoc:
+  class ReadOnlyRecord < ActiveRecordError #:nodoc:
   end
-  class Rollback < StandardError #:nodoc:
+  class Rollback < ActiveRecordError #:nodoc:
+  end
+  
+  class DangerousAttributeError < ActiveRecordError #:nodoc:
   end
   
   # Raised when you've tried to access a column, which wasn't
diff --git a/activerecord/test/attribute_methods_test.rb b/activerecord/test/attribute_methods_test.rb
index c031d78357..f16b264c35 100755
--- a/activerecord/test/attribute_methods_test.rb
+++ b/activerecord/test/attribute_methods_test.rb
@@ -53,6 +53,43 @@ class AttributeMethodsTest < Test::Unit::TestCase
     topic = Topic.create("content" => myobj)
     topic.freeze
     assert_equal myobj, topic.content
-    
+  end
+  
+  def test_kernel_methods_not_implemented_in_activerecord
+    %w(test name display y).each do |method|
+      assert_equal false, ActiveRecord::Base.instance_method_already_implemented?(method), "##{method} is defined"
+    end
+  end
+  
+  def test_primary_key_implemented
+    assert_equal true, Class.new(ActiveRecord::Base).instance_method_already_implemented?('id')
+  end
+  
+  def test_defined_kernel_methods_implemented_in_model
+    %w(test name display y).each do |method|
+      klass = Class.new ActiveRecord::Base
+      klass.class_eval "def #{method}() 'defined #{method}' end"
+      assert_equal true, klass.instance_method_already_implemented?(method), "##{method} is not defined"
+    end
+  end
+  
+  def test_defined_kernel_methods_implemented_in_model_abstract_subclass
+    %w(test name display y).each do |method|
+      abstract = Class.new ActiveRecord::Base
+      abstract.class_eval "def #{method}() 'defined #{method}' end"
+      abstract.abstract_class = true
+      klass = Class.new abstract
+      assert_equal true, klass.instance_method_already_implemented?(method), "##{method} is not defined"
+    end
+  end
+  
+  def test_raises_dangerous_attribute_error_when_defining_activerecord_method_in_model
+    %w(save create_or_update).each do |method|
+      klass = Class.new ActiveRecord::Base
+      klass.class_eval "def #{method}() 'defined #{method}' end"
+      assert_raises ActiveRecord::DangerousAttributeError do
+        klass.instance_method_already_implemented?(method)
+      end
+    end
   end
 end