930160 - crash in java.lang.NullPointerException: at org.mozilla.gecko.home.TopSitesPage$1.onItemClick(TopSitesPage.java)

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: Awesomescreen, defect)

Description

[Aaron Train [:aaronmt]]

This bug was filed from the Socorro interface and is 
report bp-80fee604-f17c-49b4-b5a8-731f92131022.
=============================================================

java.lang.NullPointerException
	at org.mozilla.gecko.home.TopSitesPage$1.onItemClick(TopSitesPage.java:174)
	at org.mozilla.gecko.home.HomeListView$1.onItemClick(HomeListView.java:112)
	at android.widget.AdapterView.performItemClick(AdapterView.java:297)

Comment 1

[Sriram Ramasubramanian [:sriram]]

Attachment: Patch

Not sure what could cause the grid adapter to be null.
Prevention is better than cure.

Comment 2

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

Comment on attachment 821904 [details] [diff] [review]
Patch

Is it OK to continue in the function? Or should we just return? Just asking.

Comment 3

[Sriram Ramasubramanian [:sriram]]

The function should continue. We're just averting a crash (when the gridAdapter is null -- which means, no grid is shown -- which is weird).

Comment 4

[Lucas Rocha (:lucasr)]

Comment on attachment 821904 [details] [diff] [review]
Patch

Review of attachment 821904 [details] [diff] [review]:
-----------------------------------------------------------------

Same here, I'd prefer to wait for steps to reproduce before landing something like this. This can be a symptom of a broader bug in our UI that we don't want to hide. Unless this is a top crasher?

Comment 5

[Tyler Downer [He/Him]]

Ok, possible STR:
Open nightly.
Have about:home opened to Top Sites
Tap one of the links (not the top site screengrabs) quickly and repeatedly (over 5 times) and you will crash

Comment 6

[Lucas Rocha (:lucasr)]

Sriram, could you have a look at this again and see if you can find the root cause of this bug? Tyler has provided STR in comment #5.

Comment 7

[Aaron Train [:aaronmt]]

26 is affected here according to the summary in comment #0, although the number of crashes is quite small.

Comment 9

[Lucas Rocha (:lucasr)]

Attachment: Discard item clicks on top sites after the fragment gets destroyed (r=mfinkle)

Comment 10

[Lucas Rocha (:lucasr)]

Comment on attachment 8364334 [details] [diff] [review]
Discard item clicks on top sites after the fragment gets destroyed (r=mfinkle)

Managed to reproduce this locally using the STR from comment #5. It seems there's a short window of time where pending item click events might get handled after the fragment gets destroyed.

Comment 11

[Lucas Rocha (:lucasr)]

https://hg.mozilla.org/integration/fx-team/rev/0e7f583a8f1a

Comment 12

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/0e7f583a8f1a