From d5f71a448dd8724a97e589a94d974d84248c477f Mon Sep 17 00:00:00 2001
From: "Manu Mtz.-Almeida" <manu.valladolid@gmail.com>
Date: Sun, 2 Oct 2016 17:15:23 +0200
Subject: [PATCH] fix(view-controller): dismiss does not crash when called more
 than once

fixes #8395
---
 src/navigation/test/view-controller.spec.ts | 18 ++++++++++++++++++
 src/navigation/view-controller.ts           |  4 ++++
 2 files changed, 22 insertions(+)

diff --git a/src/navigation/test/view-controller.spec.ts b/src/navigation/test/view-controller.spec.ts
index f11d6f6b74..078de5741a 100644
--- a/src/navigation/test/view-controller.spec.ts
+++ b/src/navigation/test/view-controller.spec.ts
@@ -117,8 +117,26 @@ describe('ViewController', () => {
 
       viewController.dismiss('didDismiss data');
     }, 10000);
+
+    it('should not crash when calling dismiss() twice', (done) => {
+      // arrange
+      let viewController = mockView();
+      let navControllerBase = mockNavController();
+      mockViews(navControllerBase, [viewController]);
+
+      viewController.onDidDismiss((data: any) => {
+        expect(data).toEqual('didDismiss data');
+        setTimeout(() => {
+          viewController.dismiss(); // it should not crash
+          done();
+        }, 100);
+      });
+
+      viewController.dismiss('didDismiss data');
+    }, 10000);
   });
 
+
   afterEach(() => {
     if (subscription) {
       subscription.unsubscribe();
diff --git a/src/navigation/view-controller.ts b/src/navigation/view-controller.ts
index 34615982e3..6075824888 100644
--- a/src/navigation/view-controller.ts
+++ b/src/navigation/view-controller.ts
@@ -180,6 +180,10 @@ export class ViewController {
    *
    */
   dismiss(data?: any, role?: any, navOptions: NavOptions = {}) {
+    if (!this._nav) {
+      return Promise.resolve(false);
+    }
+
     let options = merge({}, this._leavingOpts, navOptions);
     this._onWillDismiss && this._onWillDismiss(data, role);
     return this._nav.remove(this._nav.indexOf(this), 1, options).then(() => {