3 files changed, 17 insertions, 7 deletions
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 29e0c977ce..4726a68f69 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -1,5 +1,3 @@
-# -*- coding: utf-8 -*-
-
 require 'active_support/core_ext/array/conversions'
 require 'active_support/core_ext/string/inflections'
 require 'active_support/core_ext/object/deep_dup'
diff --git a/activemodel/lib/active_model/validations.rb b/activemodel/lib/active_model/validations.rb
index 5f1dde4aa3..f23c920d87 100644
--- a/activemodel/lib/active_model/validations.rb
+++ b/activemodel/lib/active_model/validations.rb
@@ -162,7 +162,7 @@ module ActiveModel
           options = options.dup
           options[:if] = Array(options[:if])
           options[:if].unshift ->(o) {
-            Array(options[:on]).include?(o.validation_context)
+            !(Array(options[:on]) & Array(o.validation_context)).empty?
           }
         end
 
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+.