828480 - java.lang.NullPointerException: at org.mozilla.gecko.AllPagesTab.setSuggestionsEnabled(AllPagesTab.java)

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: General, defect)

Description

[Scoobidiver (away)]

This bug tracks crashes not fixed by bug 816902.

Here is a crash report :bp-a3b1db88-e2be-452d-8667-0e8cf2130109.

java.lang.NullPointerException
	at org.mozilla.gecko.AllPagesTab.setSuggestionsEnabled(AllPagesTab.java:606)
	at org.mozilla.gecko.AllPagesTab.access$900(AllPagesTab.java:53)
	at org.mozilla.gecko.AllPagesTab$5.onClick(AllPagesTab.java:589)
	at android.view.View.performClick(View.java:4198)
	at android.view.View$PerformClick.run(View.java:17158)
	at android.os.Handler.handleCallback(Handler.java:615)
	at android.os.Handler.dispatchMessage(Handler.java:92)
	at android.os.Looper.loop(Looper.java:137)
	at android.app.ActivityThread.main(ActivityThread.java:4918)
	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:1004)
	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:771)
	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.gecko.AllPagesTab.setSuggestionsEnabled%28AllPagesTab.java%29

Comment 1

[Brian Nicholson (:bnicholson)]

Bug 816902 immediately removed these listeners to prevent them from being triggered multiple times here: http://hg.mozilla.org/releases/mozilla-release/file/7e5736897abb/mobile/android/base/awesomebar/AllPagesTab.java#l585

The only place we set mSuggestionsPrompt to null is here: http://hg.mozilla.org/releases/mozilla-release/file/7e5736897abb/mobile/android/base/awesomebar/AllPagesTab.java#l633

That means setSuggestionsEnabled() was already called prior to the NPE, which means that multiple onClick() calls are still possible with the current implementation. I assume the click event isn't synchronously dispatched, so users could still queue up multiple click events before onClick() is first called. I found this same issue described here: http://stackoverflow.com/questions/10848157/android-prevent-multiple-onclick-events-on-a-button-that-has-been-disabled

An easy fix would be to add a null check for mSuggestionsPrompt to the beginning of setSuggestionsEnabled(), but I'd be concerned that the Runnable at http://hg.mozilla.org/releases/mozilla-release/file/7e5736897abb/mobile/android/base/awesomebar/AllPagesTab.java#l629 could potentially be executed after the second call to setSuggestionsEnabled() has already begun (which would cause a NPE for mSuggestionsPrompt somewhere later in the method). A fix that should work would be to create a class-level boolean that's toggled on the first call, but I hate creating a boolean for something so trivial...

Comment 2

[Brian Nicholson (:bnicholson)]

Attachment: Add null check for mSuggestionsOptInPrompt

This just adds a null check to the beginning of setSuggestionsEnabled(). We can look into other fixes if we still have crashes as speculated in comment 1.

Comment 3

[Brian Nicholson (:bnicholson)]

https://hg.mozilla.org/integration/mozilla-inbound/rev/9175ec4d6e68

Comment 4

[Brian Nicholson (:bnicholson)]

Comment on attachment 702055 [details] [diff] [review]
Add null check for mSuggestionsOptInPrompt

[Approval Request Comment]
Bug caused by (feature/regressing bug #): bug 769145
User impact if declined: crashes if suggestions prompt response is clicked repeatedly
Testing completed (on m-c, etc.): just landed m-i
Risk to taking this patch (and alternatives if risky): very low risk - just adds a null pointer check
String or UUID changes made by this patch: none

Comment 5

[Ed Morley [:emorley]]

https://hg.mozilla.org/mozilla-central/rev/9175ec4d6e68

Comment 6

[Alex Keybl [:akeybl]]

Comment on attachment 702055 [details] [diff] [review]
Add null check for mSuggestionsOptInPrompt

Mobile only null check, good for b3 and Aurora.

Comment 7

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-beta/rev/1552a9bf3c99

Comment 8

[Ryan VanderMeulen [:RyanVM]]

(Also, this is in my queue to land on Aurora once it reopens)

Comment 9

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/releases/mozilla-aurora/rev/87a809f235a2