Subclass instantiation doesn't try to explicitly require the corresponding subclass. Closes #6840.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5751 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

4 files changed, 41 insertions, 9 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 95cae514ac..72c599fb83 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Subclass instantiation doesn't try to explicitly require the corresponding subclass.  #6840 [leei, Jeremy Kemper]
+
 * fix faulty inheritance tests and that eager loading grabs the wrong inheritance column when the class of your association is an STI subclass. Closes #6859 [protocool]
 
 * Consolidated different create and create! versions to call through to the base class with scope. This fixes inconsistencies, especially related to protected attribtues. Closes #5847 [Alexander Dymo, Tobias Luetke]
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index 05eaf7b458..8a1768dba6 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -947,10 +947,6 @@ module ActiveRecord
           end
         end
 
-        def require_association_class(class_name)
-          require_association(Inflector.underscore(class_name)) if class_name
-        end
-
         def add_multiple_associated_save_callbacks(association_name)
           method_name = "validate_associated_records_for_#{association_name}".to_sym
           define_method(method_name) do
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index 08df7e6f2e..b0ff70e5af 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -1054,8 +1054,6 @@ module ActiveRecord #:nodoc:
                 allocate
 
               else
-                require_association_class(subclass_name)
-
                 # Ignore type if no column is present since it was probably
                 # pulled in from a sloppy join.
                 unless columns_hash.include?(inheritance_column)
@@ -1354,9 +1352,9 @@ module ActiveRecord #:nodoc:
         def compute_type(type_name)
           modularized_name = type_name_with_module(type_name)
           begin
-            instance_eval(modularized_name)
-          rescue NameError => e
-            instance_eval(type_name)
+            class_eval(modularized_name, __FILE__, __LINE__)
+          rescue NameError
+            class_eval(type_name, __FILE__, __LINE__)
           end
         end
 
diff --git a/activerecord/test/inheritance_test.rb b/activerecord/test/inheritance_test.rb
index 20f9225004..8b0d70cfa3 100755
--- a/activerecord/test/inheritance_test.rb
+++ b/activerecord/test/inheritance_test.rb
@@ -167,3 +167,39 @@ class InheritanceTest < Test::Unit::TestCase
       Company.set_inheritance_column('type')
     end
 end
+
+
+class InheritanceComputeTypeTest < Test::Unit::TestCase
+  fixtures :companies
+
+  def setup
+    Dependencies.log_activity = true
+  end
+
+  def teardown
+    Dependencies.log_activity = false
+    self.class.const_remove :FirmOnTheFly rescue nil
+    Firm.const_remove :FirmOnTheFly rescue nil
+  end
+
+  def test_instantiation_doesnt_try_to_require_corresponding_file
+    foo = Firm.find(:first).clone
+    foo.ruby_type = foo.type = 'FirmOnTheFly'
+    foo.save!
+
+    # Should fail without FirmOnTheFly in the type condition.
+    assert_raise(ActiveRecord::RecordNotFound) { Firm.find(foo.id) }
+
+    # Nest FirmOnTheFly in the test case where Dependencies won't see it.
+    self.class.const_set :FirmOnTheFly, Class.new(Firm)
+    assert_raise(ActiveRecord::SubclassNotFound) { Firm.find(foo.id) }
+
+    # Nest FirmOnTheFly in Firm where Dependencies will see it.
+    # This is analogous to nesting models in a migration.
+    Firm.const_set :FirmOnTheFly, Class.new(Firm)
+
+    # And instantiate will find the existing constant rather than trying
+    # to require firm_on_the_fly.
+    assert_nothing_raised { assert_kind_of Firm::FirmOnTheFly, Firm.find(foo.id) }
+  end
+end