Bug: Intermittent [tier2] browser/components/sessionstore/test/browser_scrollPositions.js | reloading retains scroll positions - Got "null", expected "{\"scroll\":\"193,211\"}"
Status: RESOLVED
Priority: P5
Resolution: INCOMPLETE
Created: 2021-06-11 23:19:27+00:00
Resolved: 2021-07-06 17:03:41+00:00

**Filed by:** apavel [at] mozilla.com
**Parsed log:** https://treeherder.mozilla.org/logviewer?job_id=342496167&repo=autoland
**Full log:** https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/Ux8w4Ku-SJe38gI5q3jf1w/runs/0/artifacts/public/logs/live_backing.log

---
```
task 2021-06-11T11:59:58.913Z] 11:59:58     INFO - TEST-START | browser/components/sessionstore/test/browser_scrollPositions.js
[task 2021-06-11T11:59:58.920Z] 11:59:58     INFO - GECKO(10120) | [Parent 7916, IPC I/O Parent] WARNING: file /builds/worker/checkouts/gecko/ipc/chromium/src/base/process_util_win.cc:167
[task 2021-06-11T12:00:10.837Z] 12:00:10     INFO - TEST-INFO | started process screenshot
[task 2021-06-11T12:00:10.912Z] 12:00:10     INFO - TEST-INFO | screenshot: exit 0
[task 2021-06-11T12:00:10.913Z] 12:00:10     INFO - Buffered messages logged at 11:59:58
[task 2021-06-11T12:00:10.913Z] 12:00:10     INFO - Entering test bound test_scroll_nested
[task 2021-06-11T12:00:10.914Z] 12:00:10     INFO - Buffered messages logged at 12:00:00
[task 2021-06-11T12:00:10.914Z] 12:00:10     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | scroll is fine - 
[task 2021-06-11T12:00:10.915Z] 12:00:10     INFO - Buffered messages logged at 12:00:02
[task 2021-06-11T12:00:10.915Z] 12:00:10     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | scroll is fine - 
[task 2021-06-11T12:00:10.916Z] 12:00:10     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | scroll position #1 has been duplicated correctly - 
[task 2021-06-11T12:00:10.917Z] 12:00:10     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | scroll position #2 has been duplicated correctly - 
[task 2021-06-11T12:00:10.917Z] 12:00:10     INFO - Buffered messages logged at 12:00:03
[task 2021-06-11T12:00:10.917Z] 12:00:10     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | scroll is fine - 
[task 2021-06-11T12:00:10.918Z] 12:00:10     INFO - Buffered messages logged at 12:00:05
[task 2021-06-11T12:00:10.918Z] 12:00:10     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | no scroll stored - 
[task 2021-06-11T12:00:10.919Z] 12:00:10     INFO - Leaving test bound test_scroll_nested
[task 2021-06-11T12:00:10.919Z] 12:00:10     INFO - Entering test bound test_scroll
[task 2021-06-11T12:00:10.919Z] 12:00:10     INFO - File browser_scrollPositions_sample.html has COOP headers enabled
[task 2021-06-11T12:00:10.920Z] 12:00:10     INFO - Buffered messages logged at 12:00:10
[task 2021-06-11T12:00:10.920Z] 12:00:10     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | scroll is fine - 
[task 2021-06-11T12:00:10.921Z] 12:00:10     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | scroll position has been duplicated correctly - 
[task 2021-06-11T12:00:10.921Z] 12:00:10     INFO - Buffered messages finished
[task 2021-06-11T12:00:10.922Z] 12:00:10     INFO - TEST-UNEXPECTED-FAIL | browser/components/sessionstore/test/browser_scrollPositions.js | reloading retains scroll positions - Got "null", expected "{\"scroll\":\"193,211\"}"
[task 2021-06-11T12:00:10.922Z] 12:00:10     INFO - Stack trace:
[task 2021-06-11T12:00:10.922Z] 12:00:10     INFO - chrome://mochikit/content/browser-test.js:test_is:1362
[task 2021-06-11T12:00:10.922Z] 12:00:10     INFO - chrome://mochitests/content/browser/browser/components/sessionstore/test/head.js:checkScroll:630
[task 2021-06-11T12:00:10.923Z] 12:00:10     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | force-reload resets scroll positions - 
[task 2021-06-11T12:00:10.923Z] 12:00:10     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | no scroll stored - 
[task 2021-06-11T12:00:10.924Z] 12:00:10     INFO - Leaving test bound test_scroll
[task 2021-06-11T12:00:10.924Z] 12:00:10     INFO - Entering test bound test_scroll
[task 2021-06-11T12:00:11.967Z] 12:00:11     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | scroll is fine - 
[task 2021-06-11T12:00:12.064Z] 12:00:12     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | scroll position has been duplicated correctly - 
[task 2021-06-11T12:00:12.112Z] 12:00:12     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | reloading retains scroll positions - 
[task 2021-06-11T12:00:12.158Z] 12:00:12     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | force-reload resets scroll positions - 
[task 2021-06-11T12:00:13.145Z] 12:00:13     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | no scroll stored - 
[task 2021-06-11T12:00:13.151Z] 12:00:13     INFO - Leaving test bound test_scroll
[task 2021-06-11T12:00:13.152Z] 12:00:13     INFO - Entering test bound test_scroll
[task 2021-06-11T12:00:14.231Z] 12:00:14     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | scroll is fine - 
[task 2021-06-11T12:00:14.330Z] 12:00:14     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | scroll position has been duplicated correctly - 
[task 2021-06-11T12:00:14.383Z] 12:00:14     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | reloading retains scroll positions - 
[task 2021-06-11T12:00:14.431Z] 12:00:14     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | force-reload resets scroll positions - 
[task 2021-06-11T12:00:15.416Z] 12:00:15     INFO - TEST-PASS | browser/components/sessionstore/test/browser_scrollPositions.js | no scroll stored - 
[task 2021-06-11T12:00:15.420Z] 12:00:15     INFO - Leaving test bound test_scroll
[task 2021-06-11T12:00:15.420Z] 12:00:15     INFO - Entering test bound test_scroll_background_tabs
[task 2021-06-11T12:00:15.421Z] 12:00:15     INFO - File browser_scrollPositions_sample.html has COOP headers enabled
```