1402549 - Intermittent testSessionFilePreservation | Exception caught - java.lang.ArrayIndexOutOfBoundsException: length=3; index=3

Status: RESOLVED FIXED

(Firefox for Android Graveyard :: Session Restore, defect, P3)

Description

[Treeherder Bug Filer]

Filed by: aiakab [at] mozilla.com

https://treeherder.mozilla.org/logviewer.html#?job_id=132792519&repo=autoland

https://queue.taskcluster.net/v1/task/C29-39sSRIGOMgCdqzioVg/runs/0/artifacts/public/logs/live_backing.log

Comment 1

[Intermittent Failures Robot]

1 failures in 943 pushes (0.001 failures/push) were associated with this bug in the last 7 days.    

Repository breakdown:
* autoland: 1

Platform breakdown:
* android-4-3-armv7-api16: 1

For more details, see:
https://brasstacks.mozilla.com/orangefactor/?display=Bug&bugid=1402549&startday=2017-09-18&endday=2017-09-24&tree=all

Comment 2

[Intermittent Failures Robot]

1 failures in 824 pushes (0.001 failures/push) were associated with this bug in the last 7 days.    

Repository breakdown:
* mozilla-inbound: 1

Platform breakdown:
* android-4-3-armv7-api16: 1

For more details, see:
https://brasstacks.mozilla.com/orangefactor/?display=Bug&bugid=1402549&startday=2017-10-02&endday=2017-10-08&tree=all

Comment 3

[Firefox Bug Husbandry Bot]

https://wiki.mozilla.org/Bugmasters#Intermittent_Test_Failure_Cleanup

Comment 4

[Narcis Beleuzu [:NarcisB]]

Fail started to occur on autoland:

Push: https://treeherder.mozilla.org/#/jobs?repo=autoland&revision=cffe5fb28653011fff06b44322c5104a9a157c63
Log: https://treeherder.mozilla.org/logviewer.html#?job_id=159181537&repo=autoland&lineNumber=1808

Comment 5

[Jet Villegas (inactive)]

Not a Layout test. Re-routing...

Comment 6

[Jan Henning [:JanH]]

We seem to have a tab more than expected, so I'd guessing we're hitting a session store file that was written just between these two statements:
https://dxr.mozilla.org/mozilla-central/rev/5454ed95c82a956009db2f4b04d008ec8753e61e/mobile/android/tests/browser/robocop/src/org/mozilla/gecko/tests/testSessionFilePreservation.java#48-49

So two things to do here:
1. Let the session JSON verification function compare the actual and expected tab count as well, so we don't crash and instead wait up to SESSION_TIMEOUT until the correct session store file has eventually been written after that temporary tab is closed again
2. Find a better way of triggering a session store write, possibly by introducing a dedicated EventDispatcher message that we can use during testing.

Comment 7

[Intermittent Failures Robot]

1 failures in 735 pushes (0.001 failures/push) were associated with this bug in the last 7 days.    

Repository breakdown:
* autoland: 1

Platform breakdown:
* android-4-3-armv7-api16: 1

For more details, see:
https://brasstacks.mozilla.com/orangefactor/?display=Bug&bugid=1402549&startday=2018-01-29&endday=2018-02-04&tree=all

Comment 8

[Jan Henning [:JanH]]

Attachment: Bug 1402549 - Part 1 - Assert number of saved tabs, too.

Review commit: https://reviewboard.mozilla.org/r/226804/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/226804/

Comment 9

[Jan Henning [:JanH]]

Attachment: Bug 1402549 - Part 2 - Use something else to trigger session store activity.

Instead of adding and immediately closing a tab, which carries the risk that we
catch a session store file that was written just in-between those two
operations (although part 1 means that we should be able to handle this safely
now), we just reload the current tab.

Review commit: https://reviewboard.mozilla.org/r/226806/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/226806/

Comment 10

[Eugen Sawin [:esawin]]

Comment on attachment 8957820 [details]
Bug 1402549 - Part 1 - Assert number of saved tabs, too.

https://reviewboard.mozilla.org/r/226804/#review233238

Comment 11

[Eugen Sawin [:esawin]]

Comment on attachment 8957821 [details]
Bug 1402549 - Part 2 - Use something else to trigger session store activity.

https://reviewboard.mozilla.org/r/226806/#review233240

Comment 12

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5de3ada56349
Part 1 - Assert number of saved tabs, too. r=esawin
https://hg.mozilla.org/integration/autoland/rev/c6ad03aa476f
Part 2 - Use something else to trigger session store activity. r=esawin

Comment 13

[Arthur Iakab [arthur_iakab]]

https://hg.mozilla.org/mozilla-central/rev/5de3ada56349
https://hg.mozilla.org/mozilla-central/rev/c6ad03aa476f

Comment 14

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

https://hg.mozilla.org/releases/mozilla-beta/rev/bd194ec65d78
https://hg.mozilla.org/releases/mozilla-beta/rev/80b491577ef9