From 38a38b185a0e5ad6e20c1e9de51399c25e1536f8 Mon Sep 17 00:00:00 2001
From: Rafael <rafaelsantana3095@gmail.com>
Date: Mon, 10 Jul 2017 21:46:26 -0300
Subject: [PATCH] fix(tab-nav-bar): check if the subscription is not undefined

---
 src/lib/tabs/tab-nav-bar/tab-nav-bar.ts | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/lib/tabs/tab-nav-bar/tab-nav-bar.ts b/src/lib/tabs/tab-nav-bar/tab-nav-bar.ts
index b0a3f56c3afe..5a568146c2bf 100644
--- a/src/lib/tabs/tab-nav-bar/tab-nav-bar.ts
+++ b/src/lib/tabs/tab-nav-bar/tab-nav-bar.ts
@@ -86,7 +86,10 @@ export class MdTabNav implements AfterContentInit, OnDestroy {
 
   ngOnDestroy() {
     this._onDestroy.next();
-    this._resizeSubscription.unsubscribe();
+
+    if (this._resizeSubscription) {
+      this._resizeSubscription.unsubscribe();
+    }
   }
 
   /** Aligns the ink bar to the active link. */