I have a MainActivity which has filters MAIN and LAUNCHER set. It is mostly a single Activity based application except for few SDK screens which open in separate Activity.

My requirement is, when an user taps the push notification, I always want the MainActivity to be shown and get the Intent data in onNewIntent callback.

So I have tried the following for the pending Intent,

Option 1, this is working as expected, except when push notification tap opens app from killed state. In this state If I put the app to background using Home button and try to open the app using the Android Launcher (Recents is working correctly), a new MainActivity is pushed on top. So the Stack becomes MainActivity -> MainActivity. I can fix this by making the launchMode to singleTop. But what if the user opens another Activity from SDK in this case and puts the app to background? MainActivity -> ChatActivity?

val intent = Intent(this, MainActivity::class.java)
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_CLEAR_TOP or Intent.FLAG_ACTIVITY_SINGLE_TOP)

Option 2, set all properties like how the Android Launcher does, this solves the problem I have mentioned above. Even singletop is not required.

val intent = Intent(this, MainActivity::class.java)
            intent.setAction(Intent.ACTION_MAIN)
            intent.addCategory(Intent.CATEGORY_LAUNCHER)
            intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK or Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED)

My question, is option2 safe to use in all Android devices? Why does Android launcher push a new MainActivity if there is already a Task with the Activity, Task launched using notification pending Intent, even when both have the flag FLAG_ACTIVITY_NEW_TASK set?