improving DataMapper adapter and specs

lib/cancan/model_adapters/data_mapper_adapter.rb

@@ -5,8 +5,16 @@ module CanCan
         model_class <= DataMapper::Resource
       end
 
+      def self.override_conditions_hash_matching?(subject, conditions)
+        conditions.any? { |k,v| !k.kind_of?(Symbol) }
+      end
+
+      def self.matches_conditions_hash?(subject, conditions)
+        subject.class.all(:conditions => conditions).include?(subject) # TODO don't use a database query here for performance and other instances
+      end
+
       def database_records
-        scope = @model_class.all(:conditions => ['true=false'])
+        scope = @model_class.all(:conditions => ["0=1"])
         conditions.each do |condition|
           scope += @model_class.all(:conditions => condition)
         end

lib/cancan/model_adapters/mongoid_adapter.rb

@@ -10,7 +10,7 @@ module CanCan
       end
 
       def self.matches_conditions_hash?(subject, conditions)
-        subject.class.where(conditions).include?(subject)  # just use Mongoid's where function
+        subject.class.where(conditions).include?(subject) # TODO don't use a database query here for performance and other instances
       end
 
       def database_records