Fixed Time/Date object serialization

Time/Date objects used to be converted to_s instead of to_uaml
which made them unserializable.

activerecord/lib/active_record/base.rb

@@ -2626,8 +2626,15 @@ def attributes_with_quotes(include_primary_key = true, include_readonly_attribut
         quoted = {}
         connection = self.class.connection
         attribute_names.each do |name|
-          if column = column_for_attribute(name)
-            quoted[name] = connection.quote(read_attribute(name), column) unless !include_primary_key && column.primary
+          if (column = column_for_attribute(name)) && (include_primary_key || !column.primary)
+            value = read_attribute(name)
+
+            # We need explicit to_yaml because quote() does not properly convert Time/Date fields to YAML.
+            if value && self.class.serialized_attributes.has_key?(name) && (value.acts_like?(:date) || value.acts_like?(:time))
+              value = value.to_yaml
+            end
+
+            quoted[name] = connection.quote(value, column)
           end
         end
         include_readonly_attributes ? quoted : remove_readonly_attributes(quoted)

activerecord/test/cases/base_test.rb

@@ -1361,6 +1361,12 @@ def test_serialized_attribute
     assert_equal(myobj, topic.content)
   end
 
+  def test_serialized_time_attribute
+    myobj = Time.local(2008,1,1,1,0)
+    topic = Topic.create("content" => myobj).reload
+    assert_equal(myobj, topic.content)
+  end
+
   def test_nil_serialized_attribute_with_class_constraint
     myobj = MyObject.new('value1', 'value2')
     topic = Topic.new