fix(): handle failure in hardware back button

core/src/components.d.ts

@@ -4019,7 +4019,7 @@ export namespace Components {
     * The text to display on the ok button. Default: `OK`.
     */
     'okText': string;
-    'open': (ev?: UIEvent | undefined) => Promise<HTMLIonActionSheetElement | HTMLIonAlertElement | HTMLIonPopoverElement>;
+    'open': (ev?: UIEvent | undefined) => Promise<HTMLIonPopoverElement | HTMLIonActionSheetElement | HTMLIonAlertElement>;
     /**
     * The text to display when the select is empty.
     */

core/src/components/router/router.tsx

@@ -81,7 +81,7 @@ export class Router {
     return this.writeNavStateRoot(path, direction);
   }
 
-  @Listen('window:ionBackButton')
+  @Listen('document:ionBackButton')
   protected onBackButton(ev: BackButtonEvent) {
     ev.detail.register(0, () => this.goBack());
   }

core/src/utils/hardware-back-button.ts

@@ -9,11 +9,11 @@ interface HandlerRegister {
 
 export function startHardwareBackButton(win: Window) {
   let busy = false;
-  win.addEventListener('backbutton', () => {
+  win.document.addEventListener('backbutton', () => {
     if (busy) {
       return;
     }
-    busy = true;
+
     const handlers: HandlerRegister[] = [];
     const ev: BackButtonEvent = new CustomEvent('ionBackButton', {
       bubbles: false,
@@ -23,9 +23,10 @@ export function startHardwareBackButton(win: Window) {
         }
       }
     });
-    win.document.body.dispatchEvent(ev);
+    win.document.dispatchEvent(ev);
 
     if (handlers.length > 0) {
+      busy = true;
       let selectedPriority = Number.MIN_SAFE_INTEGER;
       let handler: Handler;
       handlers.forEach(h => {
@@ -34,9 +35,15 @@ export function startHardwareBackButton(win: Window) {
           handler = h.handler;
         }
       });
-      const result = handler!();
-      if (result != null) {
-        result.then(() => busy = false);
+      try {
+        const result = handler!();
+        if (result != null) {
+          result.then(() => (busy = false), () => (busy = false));
+        } else {
+          busy = false;
+        }
+      } catch (ev) {
+        busy = false;
       }
     }
   });

core/src/utils/overlays.ts

@@ -19,7 +19,7 @@ export function createOverlay<T extends HTMLIonOverlayElement>(element: T, opts:
   // append the overlay element to the document body
   getAppRoot(doc).appendChild(element);
 
-  doc.body.addEventListener('ionBackButton', ev => {
+  doc.addEventListener('ionBackButton', ev => {
     (ev as BackButtonEvent).detail.register(100, () => closeTopOverlay(doc));
   });