854179 - java.lang.NullPointerException: at org.mozilla.fennec.WebApp.onTabChanged(WebApp.java)

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: Web Apps (PWAs), defect, P2)

Description

[Scoobidiver (away)]

There's one crash in 22.0a1/20130323: bp-3d2fe647-3ed4-4743-be4d-4a2242130324.

java.lang.NullPointerException
	at org.mozilla.fennec.WebApp.onTabChanged(WebApp.java:236)
	at org.mozilla.gecko.Tabs$4.run(Tabs.java:518)
	at android.os.Handler.handleCallback(Handler.java:725)
	at android.os.Handler.dispatchMessage(Handler.java:92)
	at android.os.Looper.loop(Looper.java:137)
	at android.app.ActivityThread.main(ActivityThread.java:5226)
	at java.lang.reflect.Method.invokeNative(Native Method)
	at java.lang.reflect.Method.invoke(Method.java:511)
	at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
	at dalvik.system.NativeStart.main(Native Method)

More reports at:
https://crash-stats.mozilla.com/report/list?signature=java.lang.NullPointerException%3A+at+org.mozilla.fennec.WebApp.onTabChanged%28WebApp.java%29

Comment 1

[Scoobidiver (away)]

More reports also at:
https://crash-stats.mozilla.com/report/list?signature=java.lang.NullPointerException%3A+at+org.mozilla.fennec_aurora.WebApp.onTabChanged%28WebApp.java%29

Comment 2

[Jason Smith [:jsmith]]

Wes - What's the impact of this crash?

Questions I have are:

1. What Android OS version would hit this crash?
2. What STR would likely trigger this crash?
3. How likely would a user hit this crash?

Comment 3

[Wesley Johnston (:wesj)]

Attachment: Patch

Not really sure. From what I can tell on Aurora this is happening because mSplashScreen is null. I'm not exactly sure how that happens, since we only set it if we're showing the splash screen, I assume this is some case where we didn't show the splashscreen?

This may fix it...

Comment 4

[Mark Finkle (:mfinkle) (use needinfo?)]

Comment on attachment 738222 [details] [diff] [review]
Patch

I am unsure as to how this could fix the issue. It looks like mSplashScreen is null in onAnimationEnd:
http://mxr.mozilla.org/mozilla-aurora/source/mobile/android/base/WebApp.java.in#236

But it was not null shortly before that. We use mSplashScreen to start the animation:
http://mxr.mozilla.org/mozilla-aurora/source/mobile/android/base/WebApp.java.in#243

Can mSplashScreen be killed or reset to null while the animation is happening? Is the splashscreen being closed by some other means?

Doesn't this patch cause a crash here:
http://mxr.mozilla.org/mozilla-aurora/source/mobile/android/base/WebApp.java.in#130

How can you just remove initializing mSplashScreen, but still use the variable?

Comment 5

[Mark Finkle (:mfinkle) (use needinfo?)]

If we have no clues as to why mSplashScreen is null in onAnimationEnd, I think a bandaid patch would be to null check mSplashScreen here:
http://mxr.mozilla.org/mozilla-aurora/source/mobile/android/base/WebApp.java.in#236

Comment 6

[Wesley Johnston (:wesj)]

Attachment: Patch

(In reply to Mark Finkle (:mfinkle) from comment #4)
> How can you just remove initializing mSplashScreen, but still use the
> variable?

Sorry for the delay. I didn't remove it. I just moved where it was initialized to onCreate(). Maybe we're hitting onCreate while (somehow?, Maybe on a really slow phone super.onCreate() takes long enough that Gecko is running before it returns?)

http://mxr.mozilla.org/mozilla-aurora/source/mobile/android/base/WebApp.java.in#57

so that we never call showSplash and never initialize mSplashScreen. The we get a LOADED event and mSplashscreen is null.

Or maybe we're starting but never hitting onCreate... Not sure how either would happen. I added some null checks to be safe here...

Comment 7

[Wesley Johnston (:wesj)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/8f2977671264

Comment 8

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/8f2977671264

Comment 10

[Scoobidiver (away)]

Uplift to Beta 22?