Psych 4: Psych::DisallowedClass exception when unserializing a setting value (#36226).

Patch by Go MAEDA.


git-svn-id: http://svn.redmine.org/redmine/trunk@21294 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/setting.rb

@@ -106,7 +106,8 @@ class Setting < ActiveRecord::Base
     v = read_attribute(:value)
     # Unserialize serialized settings
     if available_settings[name]['serialized'] && v.is_a?(String)
-      v = YAML::load(v)
+      # YAML.load works as YAML.safe_load if Psych >= 4.0 is installed
+      v = YAML.respond_to?(:unsafe_load) ? YAML.unsafe_load(v) : YAML.load(v)
       v = force_utf8_strings(v)
     end
     v = v.to_sym if available_settings[name]['format'] == 'symbol' && !v.blank?