From b80966594495e1f8bf09a5c7adb6cfd5f39c8a8f Mon Sep 17 00:00:00 2001
From: Ken Sodemann <ken@ionic.io>
Date: Tue, 5 Sep 2017 09:35:10 -0500
Subject: [PATCH] fix(slider): guard the processing of _slides

This fixes issue ##12791
---
 src/components/slides/swiper/swiper.ts | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/components/slides/swiper/swiper.ts b/src/components/slides/swiper/swiper.ts
index 0f8ca1484b..6e387b9f53 100644
--- a/src/components/slides/swiper/swiper.ts
+++ b/src/components/slides/swiper/swiper.ts
@@ -693,8 +693,10 @@ function destroyLoop(s: Slides) {
   eachChild(s._wrapper, '.' + CLS.slide + '.' + CLS.slideDuplicate, ele => {
     ele.parentElement.removeChild(ele);
   });
-  for (var i = 0; i < s._slides.length; i++) {
-    s._slides[i].removeAttribute('data-swiper-slide-index');
+  if (s._slides) {
+    for (var i = 0; i < s._slides.length; i++) {
+      s._slides[i].removeAttribute('data-swiper-slide-index');
+    }
   }
 }