Fixed bug in return_tagspace.

lspector · Nov 29, 2012 · b7c42e1 · b7c42e1
1 parent 5b036d8
commit b7c42e1
Showing 1 changed file with 5 additions and 3 deletions.
diff --git a/src/clojush/instructions/return.clj b/src/clojush/instructions/return.clj
@@ -74,6 +74,8 @@
 (define-registered
   return_tagspace
   (fn [state]
-    (let [top-env (top-item :environment state)
+    (if (empty? (:environment state))
-          new-env (assoc top-env :tag (:tag state))]
+      state
-      (push-item new-env :environment (pop-item :environment state)))))
+      (let [top-env (top-item :environment state)
+            new-env (assoc top-env :tag (:tag state))]
+        (push-item new-env :environment (pop-item :environment state))))))