2 files changed, 19 insertions, 6 deletions
diff --git a/activemodel/lib/active_model/serialization.rb b/activemodel/lib/active_model/serialization.rb
index 44bc9efa47..341651d00d 100644
--- a/activemodel/lib/active_model/serialization.rb
+++ b/activemodel/lib/active_model/serialization.rb
@@ -31,8 +31,9 @@ module ActiveModel
   # of the attributes hash's keys. In order to override this behavior, take a look
   # at the private method +read_attribute_for_serialization+.
   #
-  # JSON Serialization module is automatically include the <tt>ActiveModel::Serialization</tt>
-  # module, so there is no need to explicitly include it.
+  # The JSON serialization is provided by default when you include the
+  # <tt>ActiveModel::Serialization</tt> module, so there is no need to explicitly
+  # include it.
   #
   # A minimal implementation including JSON would be:
   #
diff --git a/activemodel/lib/active_model/validations/confirmation.rb b/activemodel/lib/active_model/validations/confirmation.rb
index 1b11c28087..bb2f0bd064 100644
--- a/activemodel/lib/active_model/validations/confirmation.rb
+++ b/activemodel/lib/active_model/validations/confirmation.rb
@@ -3,14 +3,16 @@ module ActiveModel
   module Validations
     class ConfirmationValidator < EachValidator # :nodoc:
       def initialize(options)
-        super
+        super({ case_sensitive: true }.merge!(options))
         setup!(options[:class])
       end
 
       def validate_each(record, attribute, value)
-        if (confirmed = record.send("#{attribute}_confirmation")) && (value != confirmed)
-          human_attribute_name = record.class.human_attribute_name(attribute)
-          record.errors.add(:"#{attribute}_confirmation", :confirmation, options.merge(attribute: human_attribute_name))
+        if (confirmed = record.send("#{attribute}_confirmation"))
+          unless confimation_value_equal?(record, attribute, value, confirmed)
+            human_attribute_name = record.class.human_attribute_name(attribute)
+            record.errors.add(:"#{attribute}_confirmation", :confirmation, options.except(:case_sensitive).merge!(attribute: human_attribute_name))
+          end
         end
       end
 
@@ -24,6 +26,14 @@ module ActiveModel
           :"#{attribute}_confirmation" unless klass.method_defined?(:"#{attribute}_confirmation=")
         end.compact)
       end
+
+      def confimation_value_equal?(record, attribute, value, confirmed)
+        if !options[:case_sensitive] && value.is_a?(String)
+          value.casecmp(confirmed) == 0
+        else
+          value == confirmed
+        end
+      end
     end
 
     module HelperMethods
@@ -55,6 +65,8 @@ module ActiveModel
       # Configuration options:
       # * <tt>:message</tt> - A custom error message (default is: "doesn't match
       #   <tt>%{translated_attribute_name}</tt>").
+      # * <tt>:case_sensitive</tt> - Looks for an exact match. Ignored by
+      #   non-text columns (+true+ by default).
       #
       # There is also a list of default options supported by every validator:
       # +:if+, +:unless+, +:on+, +:allow_nil+, +:allow_blank+, and +:strict+.