911490 - Grey screen of death when opening backgrounded Nightly: IllegalArgumentException: Wrong state class, expecting View State but received class android.support.v4.view.ViewPager$SavedState instead

Status: RESOLVED DUPLICATE of bug 912298

(Firefox for Android Graveyard :: Awesomescreen, defect)

Description

[Richard Newman [:rnewman]]

Attachment: Log

This has been interrupting my experience since probably the Fig merge. Sometimes, I'll tap a link in Twitter or Facebook, and Nightly will just stall at the grey background for the home screen. I have to open Settings and kill the app.

Here's why:

D/GeckoSessInfo(28062): Building SessionInformation from prefs: 0, 0, true, false
D/GeckoProfile(28062): Found profile dir: /data/data/org.mozilla.fennec/files/mozilla/c2kcd0q0.default
I/GeckoApp(28062): Creating BrowserHealthRecorder.
D/GeckoHealthRec(28062): Initializing. Dispatcher is org.mozilla.gecko.util.EventDispatcher@41d21728
D/GeckoHealthRec(28062): Initializing profile cache.
I/GeckoLogger(28062): fennec :: GeckoProfileInfo :: Restoring ProfileInformationCache from file.
D/GeckoHealthRec(28062): Successfully restored state. Initializing storage.
D/GeckoHealthRec(28062): Done initializing profile cache. Beginning storage init.
E/GeckoAppShell(28062): >>> REPORTING UNCAUGHT EXCEPTION FROM THREAD 1 ("main")
E/GeckoAppShell(28062): java.lang.IllegalArgumentException: Wrong state class, expecting View State but received class android.support.v4.view.ViewPager$SavedState instead. This usually happens when two views of different type have the same id in the same hierarchy. This view's id is id/home_pager. Make sure other views do not use the same id.
E/GeckoAppShell(28062): 	at android.view.View.onRestoreInstanceState(View.java:12076)
E/GeckoAppShell(28062): 	at android.view.View.dispatchRestoreInstanceState(View.java:12052)
E/GeckoAppShell(28062): 	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:2601)
E/GeckoAppShell(28062): 	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:2601)
E/GeckoAppShell(28062): 	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:2601)
E/GeckoAppShell(28062): 	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:2601)
E/GeckoAppShell(28062): 	at android.view.ViewGroup.dispatchRestoreInstanceState(ViewGroup.java:2601)
E/GeckoAppShell(28062): 	at android.view.View.restoreHierarchyState(View.java:12030)
E/GeckoAppShell(28062): 	at com.android.internal.policy.impl.PhoneWindow.restoreHierarchyState(PhoneWindow.java:1729)
E/GeckoAppShell(28062): 	at android.app.Activity.onRestoreInstanceState(Activity.java:957)
E/GeckoAppShell(28062): 	at android.app.Activity.performRestoreInstanceState(Activity.java:929)
E/GeckoAppShell(28062): 	at android.app.Instrumentation.callActivityOnRestoreInstanceState(Instrumentation.java:1164)
E/GeckoAppShell(28062): 	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2310)
E/GeckoAppShell(28062): 	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2368)
E/GeckoAppShell(28062): 	at android.app.ActivityThread.access$600(ActivityThread.java:151)
E/GeckoAppShell(28062): 	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1330)
E/GeckoAppShell(28062): 	at android.os.Handler.dispatchMessage(Handler.java:99)
E/GeckoAppShell(28062): 	at android.os.Looper.loop(Looper.java:155)
E/GeckoAppShell(28062): 	at android.app.ActivityThread.main(ActivityThread.java:5536)
E/GeckoAppShell(28062): 	at java.lang.reflect.Method.invokeNative(Native Method)
E/GeckoAppShell(28062): 	at java.lang.reflect.Method.invoke(Method.java:511)
E/GeckoAppShell(28062): 	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1074)
E/GeckoAppShell(28062): 	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:841)
E/GeckoAppShell(28062): 	at dalvik.system.NativeStart.main(Native Method)

Comment 1

[Richard Newman [:rnewman]]

Wait a while, and you'll get an ANR from this, sometimes.

Repro with 0 background processes allowed, and doing a bit of stuff on your phone.

Comment 2

[Richard Newman [:rnewman]]

Possibly relevant:

---
For those arriving here because this isn't working when using Fragments with the v4 support library, I note that the support library doesn't seem to call the View's onSaveInstanceState/onRestoreInstanceState for you; you have to explicitly call it yourself from a convenient place in the FragmentActivity or Fragment. 
---

http://stackoverflow.com/questions/3542333/how-to-prevent-custom-views-from-losing-state-across-screen-orientation-changes/3542895#3542895

Comment 3

[Richard Newman [:rnewman]]

N.B.:

* This also happens from the launcher. Correcting summary.
* Real-world failures do not trigger an ANR dialog. The user has to manually kill the app, and we have no record of the failure outside of FHR's own orphan session detection.

Marking as blocker, 'cos I'd block ship for this. I work on the product, and I'm planning to downgrade.

Comment 4

[Richard Newman [:rnewman]]

Best steps I can give you:

* Use Nightly.
* Go do something else for a few hours.
* Click a link in another app.
* Observe grey screen.
* Force-quit Nightly.
* Click link again.
* Observe successful load.

This'll probably be solved by code reading.