CLJS-1780: Records without extmaps fail to iterate

Author: thomasmulvaney

src/main/clojure/cljs/core.cljc

@@ -1778,7 +1778,10 @@
                                                 ~'__extmap)))
 
                         'IIterable
-                        `(~'-iterator [~gs] (RecordIter. 0 ~gs ~(count base-fields) [~@(map keyword base-fields)]  (-iterator ~'__extmap) ))
+                        `(~'-iterator [~gs]
+                          (RecordIter. 0 ~gs ~(count base-fields) [~@(map keyword base-fields)] (if ~'__extmap
+                                                                                                  (-iterator ~'__extmap)
+                                                                                                  (core/nil-iter))))
 
                         'IPrintWithWriter
                         `(~'-pr-writer [this# writer# opts#]

src/test/cljs/cljs/core_test.cljs

@@ -3245,6 +3245,17 @@
   (is (= (hash (keyword 'app "foo"))
          (hash (keyword "app" "foo")))))
 
+(defrecord CLJS1780 [a b c])
+
+(deftest test-cljs-1780
+  (let [record (->CLJS1780 1 2 3)]
+    (is (= (into #{} (sequence (map identity)
+                               record))
+           #{[:a 1] [:b 2] [:c 3]}))
+    (is (= (into #{} (sequence (map identity)
+                               (assoc record :d 4 :e 5)) )
+           #{[:a 1] [:b 2] [:c 3] [:d 4] [:e 5]}))))
+
 (comment
   ;; ObjMap
   ;; (let [ks (map (partial str "foo") (range 500))