CLJ-1723 Expanding transducer fails if adding nil values

Signed-off-by: Stuart Halloway <[email protected]>

Author: puredanger

src/jvm/clojure/lang/TransformerIterator.java

@@ -16,7 +16,7 @@
 import java.util.List;
 import java.util.NoSuchElementException;
 import java.util.Queue;
-import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.LinkedList;
 
 public class TransformerIterator implements Iterator {
 
@@ -169,7 +169,7 @@ public String toString() {
 }
 
 private static class Many implements Buffer {
-    private final Queue vals = new ConcurrentLinkedQueue();
+    private final Queue vals = new LinkedList();
 
     public Many(Object o1, Object o2) {
         vals.add(o1);

test/clojure/test_clojure/transducers.clj

@@ -347,7 +347,10 @@
     (is (= ["drib" "god" "hsif" "kravdraa" "tac"]
           (->> ["cat" "dog" "fish" "bird" "aardvark"]
             (eduction (map clojure.string/reverse))
-            (sort-by first))))))
+            (sort-by first)))))
+  (testing "expanding transducer with nils"
+           (is (= '(1 2 3 nil 4 5 6 nil)
+                  (eduction cat [[1 2 3 nil] [4 5 6 nil]])))))
 
 (deftest test-eduction-completion
   (testing "eduction completes inner xformed reducing fn"