From 562f879df5f1fd2aa6d2b411e67357b78a9bc249 Mon Sep 17 00:00:00 2001
From: Vito Alexander Nordloh <vito.nordloh@vitonordloh.de>
Date: Wed, 20 May 2015 23:22:52 +0200
Subject: [PATCH] intercept queue concurrency of 0

---
 lib/async.js       | 3 +++
 test/test-async.js | 7 +++++++
 2 files changed, 10 insertions(+)

diff --git a/lib/async.js b/lib/async.js
index 47ab5a723..81916fd89 100644
--- a/lib/async.js
+++ b/lib/async.js
@@ -886,6 +886,9 @@
         if (concurrency === undefined) {
             concurrency = 1;
         }
+        else if(concurrency === 0) {
+            throw new Error('Concurrency must not be zero');
+        }
         function _insert(q, data, pos, callback) {
           if (!q.started){
             q.started = true;
diff --git a/test/test-async.js b/test/test-async.js
index 6f6a74153..64c33f986 100755
--- a/test/test-async.js
+++ b/test/test-async.js
@@ -2453,6 +2453,13 @@ exports['queue default concurrency'] = function (test) {
     };
 };
 
+exports['queue zero concurrency'] = function(test){
+    test.throws(function () {
+        async.queue(function (task, callback) {}, 0);
+    });
+    test.done();
+};
+
 exports['queue error propagation'] = function(test){
     var results = [];