Cache inheritance_column. Closes #6592.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@5474 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

4 files changed, 22 insertions, 7 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index d61e3e509d..72fc8b23cc 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Cache inheritance_column.  #6592 [Stefan Kaes]
+
 * Firebird: decimal/numeric support.  #6408 [macrnic]
 
 * make add_order a tad faster. #6567 [Stefan Kaes]
diff --git a/activerecord/lib/active_record/associations.rb b/activerecord/lib/active_record/associations.rb
index f9713199d5..5921492433 100755
--- a/activerecord/lib/active_record/associations.rb
+++ b/activerecord/lib/active_record/associations.rb
@@ -1170,7 +1170,7 @@ module ActiveRecord
 
           sql << "GROUP BY #{options[:group]} " if options[:group]
  
-          add_order!(sql, options[:order])
+          add_order!(sql, options[:order], scope)
           add_limit!(sql, options, scope) if using_limitable_reflections?(join_dependency.reflections)
  
           return sanitize_sql(sql)
diff --git a/activerecord/lib/active_record/base.rb b/activerecord/lib/active_record/base.rb
index c35453f326..864cf43ef3 100755
--- a/activerecord/lib/active_record/base.rb
+++ b/activerecord/lib/active_record/base.rb
@@ -648,9 +648,10 @@ module ActiveRecord #:nodoc:
         key
       end
 
-      # Defines the column name for use with single table inheritance -- can be overridden in subclasses.
+      # Defines the column name for use with single table inheritance
+      # -- can be set in subclasses like so: self.inheritance_column = "type_id"
       def inheritance_column
-        "type"
+        @inheritance_column ||= "type".freeze
       end
 
       # Lazy-set the sequence name to the connection's default.  This method
@@ -800,7 +801,7 @@ module ActiveRecord #:nodoc:
       # Resets all the cached information about columns, which will cause them to be reloaded on the next request.
       def reset_column_information
         read_methods.each { |name| undef_method(name) }
-        @column_names = @columns = @columns_hash = @content_columns = @dynamic_methods_hash = @read_methods = nil
+        @column_names = @columns = @columns_hash = @content_columns = @dynamic_methods_hash = @read_methods = @inheritance_column = nil
       end
 
       def reset_column_information_and_inheritable_attributes_for_all_subclasses#:nodoc:
@@ -1057,7 +1058,7 @@ module ActiveRecord #:nodoc:
 
                 # Ignore type if no column is present since it was probably
                 # pulled in from a sloppy join.
-                unless self.columns_hash.include?(inheritance_column)
+                unless columns_hash.include?(inheritance_column)
                   allocate
 
                 else
diff --git a/activerecord/test/inheritance_test.rb b/activerecord/test/inheritance_test.rb
index 65f5d70a1f..6d559d8539 100755
--- a/activerecord/test/inheritance_test.rb
+++ b/activerecord/test/inheritance_test.rb
@@ -30,6 +30,7 @@ class InheritanceTest < Test::Unit::TestCase
   def test_alt_inheritance_find
     switch_to_alt_inheritance_column
     test_inheritance_find
+    switch_to_default_inheritance_column
   end
 
   def test_inheritance_find_all
@@ -41,6 +42,7 @@ class InheritanceTest < Test::Unit::TestCase
   def test_alt_inheritance_find_all
     switch_to_alt_inheritance_column
     test_inheritance_find_all
+    switch_to_default_inheritance_column
   end
 
   def test_inheritance_save
@@ -55,6 +57,7 @@ class InheritanceTest < Test::Unit::TestCase
   def test_alt_inheritance_save
     switch_to_alt_inheritance_column
     test_inheritance_save
+    switch_to_default_inheritance_column
   end
 
   def test_inheritance_condition
@@ -66,6 +69,7 @@ class InheritanceTest < Test::Unit::TestCase
   def test_alt_inheritance_condition
     switch_to_alt_inheritance_column
     test_inheritance_condition
+    switch_to_default_inheritance_column
   end
 
   def test_finding_incorrect_type_data
@@ -76,6 +80,7 @@ class InheritanceTest < Test::Unit::TestCase
   def test_alt_finding_incorrect_type_data
     switch_to_alt_inheritance_column
     test_finding_incorrect_type_data
+    switch_to_default_inheritance_column
   end
 
   def test_update_all_within_inheritance
@@ -87,6 +92,7 @@ class InheritanceTest < Test::Unit::TestCase
   def test_alt_update_all_within_inheritance
     switch_to_alt_inheritance_column
     test_update_all_within_inheritance
+    switch_to_default_inheritance_column
   end
 
   def test_destroy_all_within_inheritance
@@ -98,6 +104,7 @@ class InheritanceTest < Test::Unit::TestCase
   def test_alt_destroy_all_within_inheritance
     switch_to_alt_inheritance_column
     test_destroy_all_within_inheritance
+    switch_to_default_inheritance_column
   end
 
   def test_find_first_within_inheritance
@@ -109,6 +116,7 @@ class InheritanceTest < Test::Unit::TestCase
   def test_alt_find_first_within_inheritance
     switch_to_alt_inheritance_column
     test_find_first_within_inheritance
+    switch_to_default_inheritance_column
   end
 
   def test_complex_inheritance
@@ -124,6 +132,7 @@ class InheritanceTest < Test::Unit::TestCase
   def test_alt_complex_inheritance
     switch_to_alt_inheritance_column
     test_complex_inheritance
+    switch_to_default_inheritance_column
   end
 
   def test_inheritance_without_mapping
@@ -138,7 +147,10 @@ class InheritanceTest < Test::Unit::TestCase
         c['type'] = nil
         c.save
       end
-    
-      def Company.inheritance_column() "ruby_type" end
+      [ Company, Firm, Client].each { |klass| klass.reset_column_information }
+      def Company.inheritance_column; @inheritance_column ||= "ruby_type"; end
+    end
+    def switch_to_default_inheritance_column
+      [ Company, Firm, Client].each { |klass| klass.reset_column_information }
     end
 end