IssueTracker

Component used: Navigation
Version used: 2.1.0-alpha05
Devices/Android versions reproduced on: Pixel 3XL Android 9 (physical device)

Sometimes, when an app is opened with a deeplink, if the user goes back all the way to the top of the backstack, and then back again (to the previous app which opened the deeplink), the app remains in the recents screen, and then if the user brings the app back to the foreground from the recents screen, the deeplink is handled again and the user goes BACk to the deep link destination, instead of the top level destination they were on previously. This can result in an endless loop where every time the user foregrounds the app, they end up on the deeplink destination.

Despite this issue being resolved in this ticket: https://issuetracker.google.com/issues/132754763, I am still seeing the problem in some cases. Mainly, if the Intent that contains the deeplink URI contains the NEW_TASK flag, and NOT the NEW_DOCUMENT flag, then I see this issue.  To confirm, I HAVE updated to navigation version 2.1.0-alpha05. The previous ticket indicates that the issue is solved in this version.

Sample App Description:

The attached "Navigation" app is a simple implementation of the nav component. It has 2 destinations:
Root Destination - the top level, start destination
Child Destination - A "child" destination that is reachable by clicking the button in the Root Destination.

Child Destination can be opened using the follwing deep link: http://bradball.net/child

The fragments for both destinations include a text view that lists the Flags that are present on the Activity's Intent.


Steps to reproduce the issue:
1. Install the "Navigation" app
2. With another app, create an Intent that contains the NEW_TASK flag, and a data URI of http://bradball.net/child
    - You can easily create such an intent by uses the Messages app, and creating a text with the http://bradball.net/child url in it.
3. Send the intent (in messages, click on the URL link), and in the system prompt, open it with the "Navigation" app.
4. The Navigation app correctly opens to the fragment_child destination.
5. Using the system back button, go back once (to the fragment_root destination), and then go back again (to the messages app).
6. Open the Recents screen and find the entry that shows the Navigation app. Notice that it is showing "fragment_root", which is the last place we were in that app.
7. Select the Navigation app in the recents screen.
8. Observe that it uses the deeplink again, and shows the fragment_child destination.

The attached screen record is a demonstration of the above steps, using the Messages app.

It's worth noting that if I follow the same procedure as above, but use Gmail app instead of messages, the behavior is different and I cannot reproduce the issue. When Gmail sends the intent, it adds the NEW_DOCUMENT flag (in addition to NEW_TASK). As a result, when you use the back button to go back (first to root_fragment, and then back to gmail), the task for the Navigation app is completely gone, and Navigation no longer appears in the recents screen. Since it is not there, you cannot open it and re-create the problem.