Simple way to disable XML parsing of symbol/YAML types

conversions.rb

#activesupport/lib/active_support/core_ext/hash/conversions.rb
        unless defined?(XML_PARSING)
           XML_PARSING = {
-            "symbol"       => Proc.new  { |symbol|  symbol.to_sym },
+            "symbol"       => Proc.new  { |symbol|  symbol.to_s },
             "date"         => Proc.new  { |date|    ::Date.parse(date) },
             "datetime"     => Proc.new  { |time|    ::Time.parse(time).utc rescue ::DateTime.parse(time).utc },
             "integer"      => Proc.new  { |integer| integer.to_i },
@@ -76,7 +76,7 @@ module ActiveSupport #:nodoc:
             "decimal"      => Proc.new  { |number|  BigDecimal(number) },
             "boolean"      => Proc.new  { |boolean| %w(1 true).include?(boolean.strip) },
             "string"       => Proc.new  { |string|  string.to_s },
-            "yaml"         => Proc.new  { |yaml|    YAML::load(yaml) rescue yaml },
+            "yaml"         => Proc.new  { |yaml|    yaml.to_s },