My question is concerning the Android app data backup feature configured by android:allowBackup in the manifest, as documented here. As I understand it, this backed-up app data is restored when the user uninstalls and later re-installs an app from the play store.
In this scenario, when exactly is the data restoration done? Is it:
- During installation from Play Store, before user has ability to open app
- After installation is complete, potentially allowing user to open app before the restore is done
Our users are on slow internet connections and a few have reported scenarios where data they entered shortly after a reinstall is replaced by old data from past backups. If the Google backups are to blame, this seems to suggest that the restore is done after install (#2 above), but I can't find concrete information to back this.
I'm slightly skeptical because this backup feature is enabled by default. If this overwriting can indeed happen on reinstalls, this would mean all android apps under android 6+ will have encountered issues where first-time setup data (auth tokens and such) is overwritten when a restore is applied. Does anyone have any links or anecdotal information on whether this theory is correct?