From 2bd89feb0f14562a1f2c8f86cd4c6b3ecc4862e9 Mon Sep 17 00:00:00 2001
From: Dan Bucholtz <dan.bucholtz@gmail.com>
Date: Tue, 3 Oct 2017 12:32:47 -0500
Subject: [PATCH] fix(navigation): unregister root navs when appropriate

---
 src/components/app/app.ts             | 7 +++++++
 src/components/tabs/tabs.ts           | 6 +++++-
 src/navigation/nav-controller-base.ts | 2 ++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/components/app/app.ts b/src/components/app/app.ts
index 9cdfddd293d..a33b8b01100 100644
--- a/src/components/app/app.ts
+++ b/src/components/app/app.ts
@@ -274,6 +274,13 @@ export class App {
     this._rootNavs.set(nav.id, nav);
   }
 
+  /**
+   * @hidden
+   */
+  unregisterRootNav(nav: NavigationContainer) {
+    this._rootNavs.delete(nav.id);
+  }
+
 
   getActiveNavContainers(): NavigationContainer[] {
     // for each root nav container, get it's active nav
diff --git a/src/components/tabs/tabs.ts b/src/components/tabs/tabs.ts
index 1ec729995e5..b4ba46f5520 100644
--- a/src/components/tabs/tabs.ts
+++ b/src/components/tabs/tabs.ts
@@ -301,7 +301,11 @@ export class Tabs extends Ion implements AfterViewInit, RootNode, ITabs, Navigat
    */
   ngOnDestroy() {
     this._onDestroy.next();
-    this.parent.unregisterChildNav(this);
+    if (this.parent) {
+      this.parent.unregisterChildNav(this);
+    } else {
+      this._app.unregisterRootNav(this);
+    }
   }
 
   /**
diff --git a/src/navigation/nav-controller-base.ts b/src/navigation/nav-controller-base.ts
index 86daddb2d2c..2bf1ac596a3 100644
--- a/src/navigation/nav-controller-base.ts
+++ b/src/navigation/nav-controller-base.ts
@@ -1025,6 +1025,8 @@ export class NavControllerBase extends Ion implements NavController {
     // Unregister navcontroller
     if (this.parent && this.parent.unregisterChildNav) {
       this.parent.unregisterChildNav(this);
+    } else if (this._app) {
+      this._app.unregisterRootNav(this);
     }
 
     this._destroyed = true;