Warn if app was not installed in 'internal storage'

[bertwesarg]

Is your feature request related to a problem? Please describe.

See #63 and #2595: If app was not installed into the 'internal storage' than the login credentials are lost every reboot of the phone. The consent is, that the OS should not be allowed to install the app into the external storage, but vendors may ignore this request. In my case its Nokia 3 with Android 8.1.

Describe the solution you'd like

Maybe it is at least possible that the app itself can issue a warning to the user, that it was not installed in the internal storage.

Describe alternatives you've considered

None known to me.

[nextcloud-android-bot]

GitMate.io thinks possibly related issues are #2336 (Can't view External Storage in APP), #2195 (storage path), #1814 (Nexcloud Android "Account" disappears after reboot, when nextcloud app has been moved to sdcard, sdcard formatted as internal storage (Android 6.0)), #468 (Nextcloud app doesn't show all files and directories on an external storage), and #2155 (App access.).

[tobiasKaminsky]

I am unsure how we can detect this reliable.
This vendor/device specific, e.g. I saw strange things that OS said that no external sdcard is built into, but the vendor hardwired an external sdcard and tricked Android with that. However in this case you had the mentioned problems, but without knowing/seeing it.

[phu9Suop]

Correct procedure is to assure installation in internal storage.
Without exception and instantly and immediately at the time of installation and upgrade.
Is straight thinking so difficult?

[ezaquarii]

You can set a special flag in manifest, disallowing moving the app to external storage.

The loss of functionality should be minimal, considering that it doesn't work anyway.

[AndyScherzinger]

That has already been set see: https://github.com/nextcloud/android/blob/master/src/main/AndroidManifest.xml#L86 so the app's installation (via manifest) is theoretically enforced to be installed on internal memory only while @tobiasKaminsky's comment remains true, (some) OEMs trick Android and we can't do anything about that...

So comment on the offensive yet wrong comment... yes thinking straight is easy while OEMs manipulating how Android works which is the platform the app rans on top...not so much.

[ezaquarii]

@AndyScherzinger Hm... in that case I'm out of ideas and I guess it's not our bug then. :-)

[joshtrichards]

As noted we already do this. Can't do much if the underlying OEM opts to both ignore what is already Android's default behavior and our declaration making it explicit.

Given paths faked/etc we can't reliably detect this. I also hope this has become less common four years later. Particularly given the numerous apps this sort of behavior breaks (e.g. basically anything with a service). Seems a device doing this would become unpopular real fast...