From 01f86e54883d2408b270ffd10f0cc565de0dcfcb Mon Sep 17 00:00:00 2001
From: Andre Staltz <andre@staltz.com>
Date: Wed, 25 Nov 2015 16:11:38 -0200
Subject: [PATCH] fix(expand): fix expand's concurrency behavior

Fix expand() in order to emit each next value only once. It was previously emitting those values
multiple times when a concurrency limit was set.
---
 src/operators/expand-support.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/operators/expand-support.ts b/src/operators/expand-support.ts
index ad00cc9548..7b16b1969b 100644
--- a/src/operators/expand-support.ts
+++ b/src/operators/expand-support.ts
@@ -34,8 +34,8 @@ export class ExpandSubscriber<T, R> extends OuterSubscriber<T, R> {
 
   _next(value: any): void {
     const index = this.index++;
-    this.destination.next(value);
     if (this.active < this.concurrent) {
+      this.destination.next(value);
       let result = tryCatch(this.project)(value, index);
       if (result === errorObject) {
         this.destination.error(result.e);