Bug 196274

Summary: [ Mojave WK1 iOS Sim WK2] Layout Test imported/w3c/web-platform-tests/xhr/send-redirect-post-upload.htm is a flaky crash
Product: WebKit Reporter: Shawn Roberts <sroberts>
Component: Tools / TestsAssignee: Nobody <webkit-unassigned>
Status: RESOLVED DUPLICATE    
Severity: Normal CC: achristensen, ap, cdumez, lforschler, webkit-bot-watchers-bugzilla, webkit-bug-importer
Priority: P2 Keywords: InRadar
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
See Also: https://bugs.webkit.org/show_bug.cgi?id=194523
https://bugs.webkit.org/show_bug.cgi?id=159724
Attachments:
Description Flags
Mojave WK1 Crash
none
iOS Sim Crash none

Description Shawn Roberts 2019-03-26 14:59:55 PDT 
Created attachment 366005 [details]
Mojave WK1 Crash

The following layout test is flaky on Mojave WK1 and iOS Simulator Release WK2

imported/w3c/web-platform-tests/xhr/send-redirect-post-upload.htm

Probable cause:

Test has been crashing for some time, most recent fix was https://trac.webkit.org/changeset/242723/webkit 

I can reproduce locally on Mojave WK1 with 5000 iterations I got it to crash once. (will attach crash logs).
I can reproduce the iOS Sim much easier, it crashed 9 times in 18 iterations before I stopped it (will attach crash logs).

Flakiness Dashboard:

https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=imported%2Fw3c%2Fweb-platform-tests%2Fxhr%2Fsend-redirect-post-upload.htm
Comment 1 Radar WebKit Bug Importer 2019-03-26 15:01:40 PDT 
<rdar://problem/49294363>
Comment 2 Shawn Roberts 2019-03-26 15:02:00 PDT 
Created attachment 366007 [details]
iOS Sim Crash
Comment 3 Shawn Roberts 2019-03-26 15:16:54 PDT 
Updated test expectations in https://trac.webkit.org/changeset/243521/webkit

Was marked Pass Fail before, added Crash to the expectation file.
Comment 4 Alex Christensen 2019-03-26 15:40:33 PDT 
I'll continue to try to reproduce this and look into how to fix it.
Comment 5 Alex Christensen 2019-03-27 13:02:44 PDT 
I just finished running this test 20000 times with 0 crashes.  Here is what I used to run it:

run-webkit-tests --release --iterations=100 --repeat-each=200 -1 imported/w3c/web-platform-tests/xhr/send-redirect-post-upload.htm
Comment 6 Chris Dumez 2019-03-27 13:03:49 PDT 
(In reply to Alex Christensen from comment #5)
> I just finished running this test 20000 times with 0 crashes.  Here is what
> I used to run it:
> 
> run-webkit-tests --release --iterations=100 --repeat-each=200 -1
> imported/w3c/web-platform-tests/xhr/send-redirect-post-upload.htm

Sometimes, adding -gf helps:

run-webkit-tests --release --repeat-each=200 -1 -gf imported/w3c/web-platform-tests/xhr/send-redirect-post-upload.htm
Comment 7 Shawn Roberts 2019-03-27 13:16:49 PDT 
I have used -gf as well in the past as well.

In this particular case I did:

run-webkit-tests imported/w3c/web-platform-tests/xhr/send-redirect-post-upload.htm --iterations 5000 -1 -f
Comment 8 Alexey Proskuryakov 2019-03-27 13:43:25 PDT 
To state the obvious, Mac and iOS crash signatures look quite different.
Comment 9 Alex Christensen 2019-03-28 16:02:16 PDT 

*** This bug has been marked as a duplicate of bug 159724 ***
Comment 10 Alex Christensen 2019-03-28 16:06:02 PDT 
(In reply to Alexey Proskuryakov from comment #8)
> To state the obvious, Mac and iOS crash signatures look quite different.
bug 159724 makes the two crashes the same.  Since no increased crash rate was observed in Mojave WK2, it will not affect Safari updates.