new alternative reply by email addresses

lib/validators/alternative_reply_by_email_addresses_validator.rb

@@ -0,0 +1,16 @@
+class AlternativeReplyByEmailAddressesValidator
+  def initialize(opts={})
+    @opts = opts
+  end
+
+  def valid_value?(val)
+    return true if val.blank?
+
+    validator = ReplyByEmailAddressValidator.new(@opts)
+    val.split("|").all? { |v| validator.valid_value?(v) }
+  end
+
+  def error_message
+    I18n.t('site_settings.errors.invalid_alternative_reply_by_email_addresses')
+  end
+end

lib/validators/reply_by_email_address_validator.rb

@@ -6,9 +6,9 @@ class ReplyByEmailAddressValidator
   def valid_value?(val)
     return true if val.blank?
 
-    !!(val =~ /@/i) &&
-    !!(val =~ /%{reply_key}/i) &&
-    val.gsub(/\+?%{reply_key}/i, "") != SiteSetting.notification_email
+    !!val["@"] &&
+    !!val["%{reply_key}"] &&
+    val.gsub(/\+?%{reply_key}/, "") != SiteSetting.notification_email
   end
 
   def error_message