ionViewCanLeave() breaks navigation on second call, causes blank screen

[sjdrew]

ionic 2.0.0-RC0

The new ionViewCanLeave() breaks navigation. If user tries to go back once, it is blocked fine, however if on the second try of the back button also returns false, then when eventually returns true the navigation is broken and a blank white page displays.

Easy to produce, just create tutorial app via

ionic start MyIonic2Project tutorial --v2

Then add this code to the item-details.ts file, ItemDetailsPage class:

    public trys = 0;
    ionViewCanLeave(): any {
        if (this.trys++ < 2) {
            return false;
        } else return true;
    }

Then serve the app and click to item list page, then click on a row to view item-detail page, then click back button 3 times. You will end up with blank white page.

[manucorporat]

@sjdrew WIP fix: #8410