Fix to handle MetaWhere and non-MetaWhere conditions correctly.

spec/cancan/model_adapters/active_record_adapter_spec.rb

@@ -236,6 +236,16 @@ if ENV["MODEL_ADAPTER"].nil? || ENV["MODEL_ADAPTER"] == "active_record"
       @ability.should_not be_able_to(:read, article2)
     end
 
+    it "should merge MetaWhere and non-MetaWhere conditions" do
+      @ability.can :read, Article, :priority.lt => 2
+      @ability.can :read, Article, :priority => 1
+      article1 = Article.create!(:priority => 1)
+      article2 = Article.create!(:priority => 3)
+      Article.accessible_by(@ability).should == [article1]
+      @ability.should be_able_to(:read, article1)
+      @ability.should_not be_able_to(:read, article2)
+    end
+
     it "should match any MetaWhere condition" do
       adapter = CanCan::ModelAdapters::ActiveRecordAdapter
       article1 = Article.new(:priority => 1, :name => "Hello World")

spec/cancan/rule_spec.rb

@@ -36,4 +36,11 @@ describe CanCan::Rule do
     rule = CanCan::Rule.new(true, :read, Integer, nil, nil)
     rule.associations_hash.should == {}
   end
+
+  it "should not be mergeable if conditions are not simple hashes" do
+    meta_where = OpenStruct.new(:name => 'metawhere', :column => 'test')
+    @conditions[meta_where] = :bar
+
+    @rule.should be_unmergeable
+  end
 end