Don't cast nil or empty strings to a dummy date. Closes #2789.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2966 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

@@ -1,5 +1,7 @@
 *SVN*
 
+* Don't cast nil or empty strings to a dummy date.  #2789 [Rick Bradley <rick@rickbradley.com>]
+
 * acts_as_list plays nicely with inheritance by remembering the class which declared it.  #2811 [rephorm@rephorm.com]
 
 * Fix sqlite adaptor's detection of missing dbfile or database declaration. [Nicholas Seckar]

activerecord/lib/active_record/connection_adapters/oci_adapter.rb

@@ -110,6 +110,7 @@ begin
 
         def cast_to_date_or_time(value)
           return value if value.is_a? Date
+          return nil if value.blank?
           guess_date_or_time (value.is_a? Time) ? value : cast_to_time(value)
         end