1697824 - Crash in [@ java.lang.NullPointerException: at org.mozilla.geckoview.GeckoSession$Window.passExternalWebResponse(GeckoSession.java)]

Status: RESOLVED FIXED

(GeckoView :: General, defect, P2)

Description

[Emily Toop (:fluffyemily)]

Crash report: https://crash-stats.mozilla.org/report/index/f6573496-b7df-4e13-b189-7f36f0210311

Java stack trace:

java.lang.NullPointerException
	at org.mozilla.geckoview.GeckoSession$Window.passExternalWebResponse(GeckoSession.java:1)
	at org.mozilla.gecko.GeckoThread.runUiThreadCallback(Native Method)
	at org.mozilla.gecko.GeckoThread$1.run(GeckoThread.java:2)
	at android.os.Handler.handleCallback(Handler.java:790)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loop(Looper.java:192)
	at android.app.ActivityThread.main(ActivityThread.java:6738)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:549)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:825)

Comment 1

[Kevin Brosnan [Ex-Mozilla]]

Unredacted stack is

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object java.lang.ref.Reference.get()' on a null object reference
	at org.mozilla.geckoview.GeckoSession$Window.passExternalWebResponse(GeckoSession.java:1)
	at org.mozilla.gecko.GeckoThread.runUiThreadCallback(Native Method)
	at org.mozilla.gecko.GeckoThread$1.run(GeckoThread.java:2)
	at android.os.Handler.handleCallback(Handler.java:790)
	at android.os.Handler.dispatchMessage(Handler.java:99)
	at android.os.Looper.loop(Looper.java:192)
	at android.app.ActivityThread.main(ActivityThread.java:6738)
	at java.lang.reflect.Method.invoke(Native Method)
	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:549)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:825)

About 250 crashes a day across all channels.

Comment 2

[[ex-Mozilla] Agi Sferro | :agi]

Attachment: Bug 1697824 - Don't clear GeckoSession.mOwner instance.

Having a null WeakReference<> object is a little unexpected, to avoid confusion
we set mOwner to a WeakReference<>(null) value instead to avoid
a NullPointerException.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/9287b6f4f716
Don't clear GeckoSession.mOwner instance. r=esawin

Comment 4

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/9287b6f4f716

Comment 5

[Ryan VanderMeulen [:RyanVM]]

Is this something we should uplift to Beta for 88? Please nominate if so :)

Comment 6

[[ex-Mozilla] Agi Sferro | :agi]

Comment on attachment 9213863 [details]
Bug 1697824 - Don't clear GeckoSession.mOwner instance.

Beta/Release Uplift Approval Request

• User impact if declined: Some crashes when downloading files
• Is this code covered by automated tests?: No
• Has the fix been verified in Nightly?: Yes
• Needs manual test from QE?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): The patch makes sure we never null out a WeakReference object, very limited scope
• String changes made/needed:

Comment 7

[Ryan VanderMeulen [:RyanVM]]

Comment on attachment 9213863 [details]
Bug 1697824 - Don't clear GeckoSession.mOwner instance.

Approved for Fenix 88.0.0-beta.6.

Comment 8

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/511eeee50c7d