Fix wording and only specify the behavior when it was actually defined for Hash#reject.

Author: eregon

spec/ruby/core/hash/reject_spec.rb

@@ -25,15 +25,17 @@ def h.to_a() end
     h.reject { false }.to_a.should == [[1, 2]]
   end
 
-  ruby_bug "extra states should not be copied", "2.1" do
-    it "returns Hash instance for subclasses" do
-      HashSpecs::MyHash[1 => 2, 3 => 4].reject { false }.should be_kind_of(Hash)
-      HashSpecs::MyHash[1 => 2, 3 => 4].reject { true }.should be_kind_of(Hash)
-    end
-
-    it "taints the resulting hash" do
-      h = new_hash(:a => 1).taint
-      h.reject {false}.tainted?.should == false
+  ruby_version_is "2.2" do
+    context "with extra state" do
+      it "returns Hash instance for subclasses" do
+        HashSpecs::MyHash[1 => 2, 3 => 4].reject { false }.should be_kind_of(Hash)
+        HashSpecs::MyHash[1 => 2, 3 => 4].reject { true }.should be_kind_of(Hash)
+      end
+
+      it "does not taint the resulting hash" do
+        h = new_hash(:a => 1).taint
+        h.reject {false}.tainted?.should == false
+      end
     end
   end