Demonstrates behavior of mult bug

tests.cljs

(deftest ops-test
  (testing "mult with closed tap"
    (go
     (let [a (chan 4)
           b (chan 4)
           src (chan 1)
           m (async/mult src)]

       (async/tap m a)
       (async/tap m b)

       (async/close! a)

       (async/pipe (async/to-chan (range 4)) src)

       (.log js/console "a=" (clj->js (<! (async/into [] a))))
       (.log js/console "b=" (clj->js (<! (async/into [] b))))))))

Patch:

From c579a18538ddc0570628e88735099090331bbe51 Mon Sep 17 00:00:00 2001
From: loganlinn <[email protected]>
Date: Thu, 15 May 2014 09:42:30 -0700
Subject: [PATCH] Remove extra decrement


---
 src/main/clojure/cljs/core/async.cljs | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/main/clojure/cljs/core/async.cljs b/src/main/clojure/cljs/core/async.cljs
index e94a2db..542c90b 100644
--- a/src/main/clojure/cljs/core/async.cljs
+++ b/src/main/clojure/cljs/core/async.cljs
@@ -454,7 +454,6 @@
            (reset! dctr (count chs))
            (doseq [c chs]
                (when-not (put! c val done)
-                 (swap! dctr dec)
                  (untap* m c)))
            ;;wait for all
            (when (seq chs)
-- 
1.9.2

Before patch:

a= []

After patch:

a= []
b= [ 0, 1, 2, 3 ]