don't stop at cannot definitions when there are no conditions - closes #161

lib/cancan/can_definition.rb

@@ -36,7 +36,8 @@ module CanCan
       elsif @conditions.kind_of?(Hash) && !subject_class?(subject)
         matches_conditions_hash?(subject)
       else
-        @base_behavior
+        # Don't stop at "cannot" definitions when there are conditions.
+        @conditions.empty? ? true : @base_behavior
       end
     end
 

spec/cancan/ability_spec.rb

@@ -258,6 +258,13 @@ describe CanCan::Ability do
     @ability.can?(:read, Range).should be_true
   end
 
+  it "should stop at cannot definition when no hash is present" do
+    @ability.can :read, :all
+    @ability.cannot :read, Range
+    @ability.can?(:read, 1..5).should be_false
+    @ability.can?(:read, Range).should be_false
+  end
+
   it "should allow to check ability for Module" do
     module B; end
     class A; include B; end