1297772 - Still crashing in NullPointerException: Attempt to invoke virtual method 'void org.mozilla.gecko.toolbar.BackButton.setEnabled(boolean)' on a null object reference

Status: RESOLVED DUPLICATE of bug 1079874

(Firefox for Android Graveyard :: General, defect, P1)

Description

[Kevin Brosnan [Ex-Mozilla]]

This is still happening in the wild.

+++ This bug was initially created as a clone of Bug #1256596 +++

Preconditions: Nexus 9, Android N, split screen mode.

After resizing Fennec's screen to be very small (phone-like) I get the following crash:

> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: java.lang.NullPointerException: Attempt to invoke virtual method 'void org.mozilla.gecko.toolbar.BackButton.setEnabled(boolean)' on a null object reference
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at org.mozilla.gecko.toolbar.BrowserToolbarTabletBase.<init>(BrowserToolbarTabletBase.java:57)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at org.mozilla.gecko.toolbar.BrowserToolbarTablet.<init>(BrowserToolbarTablet.java:36)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at org.mozilla.gecko.toolbar.BrowserToolbar.create(BrowserToolbar.java:164)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at org.mozilla.gecko.BrowserApp.onCreateView(BrowserApp.java:290)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.app.Activity.onCreateView(Activity.java:5840)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.support.v4.app.BaseFragmentActivityHoneycomb.onCreateView(Unknown Source)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.support.v4.app.FragmentActivity.onCreateView(Unknown Source)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:777)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:727)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.rInflate(LayoutInflater.java:858)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.rInflate(LayoutInflater.java:861)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.rInflate(LayoutInflater.java:861)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.rInflate(LayoutInflater.java:861)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.rInflateChildren(LayoutInflater.java:821)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.inflate(LayoutInflater.java:518)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.inflate(LayoutInflater.java:426)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.view.LayoutInflater.inflate(LayoutInflater.java:377)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at com.android.internal.policy.PhoneWindow.setContentView(PhoneWindow.java:400)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at android.app.Activity.setContentView(Activity.java:2387)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at org.mozilla.gecko.GeckoApp.onCreate(GeckoApp.java:1276)
> 03-15 10:37:54.145  5178  5178 E GeckoCrashHandler: 	at org.mozilla.gecko.BrowserApp.onCreate(BrowserApp.java:592)

Comment 1

[Mike Kaply [:mkaply]]

Do you have any smaller devices (5/6) that recreate this?

Or is this tablet only?

(I'm trying to recreate on my Nexus 5 but I'm not seeing it)

Comment 2

[Kevin Brosnan [Ex-Mozilla]]

This requires Android 7.0 and split screen. A Nexus 5 won't be able to reproduce (a 5x might be able). There are 38 crashes a week, so it does not seem to be super common.

Comment 3

[Mike Kaply [:mkaply]]

Sorry, it is a 5X with Android 7 and I'm not crashing. So it might be tablet specific.

Comment 4

[Kevin Brosnan [Ex-Mozilla]]

It is not tablet specific. We have crashes from all the Nexus devices that meet the Android 7.0 requirements. Nexus 5x, Nexus 6, Nexus 6p and Nexus 9.

Comment 5

[Sebastian Kaspari (:sebastian; :pocmo)]

Do we have any STR? I can't reproduce on an N9 by resizing the app window (like in bug 1256596).

Comment 6

[Sebastian Kaspari (:sebastian; :pocmo)]

.. okay, I have STR:

On an N9 (might work in landscape on phones too):

* Go into split screen mode with two random apps.
* Resize one app to be pretty small, like a phone screen.
* Select the small application, press the "recent apps" button and close the app
* Now launch Firefox in the small app window

-> Crash.

From the crash I assume: Android's resource system loads the phone layout (because our small window is small like a phone). Our code detects that we are running on a tablet and tries to initialize the toolbar code, assuming we loaded the tablet layout. Crash: Some UI elements can't be found (like the back button in the toolbar).

We had problems like this in the past because our HardwareUtils.isTablet() is not in sync with Android's way of determining which resources to load (See bug 1277379). Even if we would fix this root cause: We'd load the phone UI and when resizing the application we would not switch to the tablet layout automatically. Normally Android would recreate the activity and load the "bigger" resources but for a bunch of reasons we are handling configuration changes ourselves and have no way of switching the UI on the fly.

Comment 7

[Sebastian Kaspari (:sebastian; :pocmo)]

We landed a speculative patch for this in Firefox 50 (bug 1079874) - and I only see crash reports for up to 49.

Comment 8

[Sebastian Kaspari (:sebastian; :pocmo)]

(In reply to Sebastian Kaspari (:sebastian) from comment #6)
> .. okay, I have STR:
> 
> On an N9 (might work in landscape on phones too):
> 
> * Go into split screen mode with two random apps.
> * Resize one app to be pretty small, like a phone screen.
> * Select the small application, press the "recent apps" button and close the
> app
> * Now launch Firefox in the small app window
> 
> -> Crash.

Those STR actually trigger a different crash / stack trace (bug 1296712).

Comment 9

[Sebastian Kaspari (:sebastian; :pocmo)]

(In reply to Sebastian Kaspari (:sebastian) from comment #7)
> We landed a speculative patch for this in Firefox 50 (bug 1079874) - and I
> only see crash reports for up to 49.

I requested uplift to Beta/49 in bug 1079874.