From 79885751e2410fc0070f771d54ba163da796103c Mon Sep 17 00:00:00 2001
From: Kang Cheng <me@chengkang.pw>
Date: Sun, 29 Oct 2017 15:39:45 -0700
Subject: [PATCH 1/2] fix issue #1846

---
 src/components/tabs/tabs.vue | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/src/components/tabs/tabs.vue b/src/components/tabs/tabs.vue
index d99b9066..01b50b9e 100644
--- a/src/components/tabs/tabs.vue
+++ b/src/components/tabs/tabs.vue
@@ -310,6 +310,16 @@
             },
             handleResize(){
                 this.updateNavScroll();
+            },
+            isInsideHiddenElement () {
+                let parentNode = this.$el.parentNode;
+                while(parentNode) {
+                    if (parentNode.style.display === 'none') {
+                        return parentNode;
+                    }
+                    parentNode = parentNode.parentNode;
+                }
+                return false;
             }
         },
         watch: {
@@ -329,6 +339,18 @@
             this.showSlot = this.$slots.extra !== undefined;
             this.observer = elementResizeDetectorMaker();
             this.observer.listenTo(this.$refs.navWrap, this.handleResize);
+
+            const hiddenParentNode = this.isInsideHiddenElement();
+            if (hiddenParentNode) {
+                const mutationObserver = new MutationObserver(() => {
+                    if (hiddenParentNode.style.display !== 'none') {
+                        this.updateBar();
+                        mutationObserver.disconnect();
+                    }
+                });
+
+                mutationObserver.observe(hiddenParentNode, { attributes: true, childList: true, characterData: true, attributeFilter: ['style'] });
+            }
         },
         beforeDestroy() {
             this.observer.removeListener(this.$refs.navWrap, this.handleResize);

From 3be0aa121c69ffdedb5578e7288eb3cd973acfb4 Mon Sep 17 00:00:00 2001
From: Kang Cheng <me@chengkang.pw>
Date: Mon, 30 Oct 2017 00:33:31 -0700
Subject: [PATCH 2/2] Import custom MutationObserver; remove mutation observer
 before component get destroyed

---
 src/components/tabs/tabs.vue | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/components/tabs/tabs.vue b/src/components/tabs/tabs.vue
index 01b50b9e..0773261e 100644
--- a/src/components/tabs/tabs.vue
+++ b/src/components/tabs/tabs.vue
@@ -26,7 +26,7 @@
 <script>
     import Icon from '../icon/icon.vue';
     import Render from '../base/render';
-    import { oneOf } from '../../utils/assist';
+    import { oneOf, MutationObserver } from '../../utils/assist';
     import Emitter from '../../mixins/emitter';
     import elementResizeDetectorMaker from 'element-resize-detector';
 
@@ -342,18 +342,19 @@
 
             const hiddenParentNode = this.isInsideHiddenElement();
             if (hiddenParentNode) {
-                const mutationObserver = new MutationObserver(() => {
+                this.mutationObserver = new MutationObserver(() => {
                     if (hiddenParentNode.style.display !== 'none') {
                         this.updateBar();
-                        mutationObserver.disconnect();
+                        this.mutationObserver.disconnect();
                     }
                 });
 
-                mutationObserver.observe(hiddenParentNode, { attributes: true, childList: true, characterData: true, attributeFilter: ['style'] });
+                this.mutationObserver.observe(hiddenParentNode, { attributes: true, childList: true, characterData: true, attributeFilter: ['style'] });
             }
         },
         beforeDestroy() {
             this.observer.removeListener(this.$refs.navWrap, this.handleResize);
+            this.mutationObserver.disconnect();
         }
     };
 </script>