Bug: Intermittent browser/components/urlbar/tests/browser/browser_stop_pending.js | uncaught exception - TypeError: can't access property "closing", aTab is undefined at _tabAttrModified@chrome://browser/content/tabbrowser.js:1448:11
Status: RESOLVED
Priority: P5
Resolution: DUPLICATE
Created: 2021-12-20 23:37:15+00:00
Resolved: 2022-08-12 20:36:06+00:00

**Filed by:** mlaza [at] mozilla.com
**Parsed log:** https://treeherder.mozilla.org/logviewer?job_id=361928231&repo=autoland
**Full log:** https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/aYDy7Z94TimZboGqfZ3Tgw/runs/0/artifacts/public/logs/live_backing.log

---
```
[task 2021-12-20T22:47:04.161Z] 22:47:04     INFO - TEST-PASS | browser/components/urlbar/tests/browser/browser_stop_pending.js | The URL bar change handler should have been called by the time the page was loaded - 
[task 2021-12-20T22:47:04.161Z] 22:47:04     INFO - Buffered messages logged at 22:47:04
[task 2021-12-20T22:47:04.161Z] 22:47:04     INFO - Leaving test bound testCorrectUrlBarAfterGoingBackDuringAnotherLoad
[task 2021-12-20T22:47:04.162Z] 22:47:04     INFO - Entering test bound testCorrectUrlBarAfterReloadingDuringSlowPageLoad
[task 2021-12-20T22:47:04.162Z] 22:47:04     INFO - Buffered messages finished
[task 2021-12-20T22:47:04.163Z] 22:47:04     INFO - TEST-UNEXPECTED-FAIL | browser/components/urlbar/tests/browser/browser_stop_pending.js | uncaught exception - TypeError: can't access property "closing", aTab is undefined at _tabAttrModified@chrome://browser/content/tabbrowser.js:1448:11
[task 2021-12-20T22:47:04.163Z] 22:47:04     INFO - onProgressChange@chrome://browser/content/tabbrowser.js:6377:18
[task 2021-12-20T22:47:04.163Z] 22:47:04     INFO - 
[task 2021-12-20T22:47:04.163Z] 22:47:04     INFO - Stack trace:
[task 2021-12-20T22:47:04.163Z] 22:47:04     INFO - chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:simpletestOnerror:1957
[task 2021-12-20T22:47:04.163Z] 22:47:04     INFO - GECKO(2249) | JavaScript error: chrome://browser/content/tabbrowser.js, line 1448: TypeError: can't access property "closing", aTab is undefined
[task 2021-12-20T22:47:04.164Z] 22:47:04     INFO - Console message: [JavaScript Error: "TypeError: can't access property "closing", aTab is undefined" {file: "chrome://browser/content/tabbrowser.js" line: 1448}]
[task 2021-12-20T22:47:04.164Z] 22:47:04     INFO - _tabAttrModified@chrome://browser/content/tabbrowser.js:1448:11
[task 2021-12-20T22:47:04.164Z] 22:47:04     INFO - onProgressChange@chrome://browser/content/tabbrowser.js:6377:18
[task 2021-12-20T22:47:04.164Z] 22:47:04     INFO - 
[task 2021-12-20T22:47:04.165Z] 22:47:04     INFO - GECKO(2249) | Saw state f0001 and status 0
[task 2021-12-20T22:47:04.165Z] 22:47:04     INFO - Console message: [JavaScript Warning: "This page is in Quirks Mode. Page layout may be impacted. For Standards Mode use “<!DOCTYPE html>”." {file: "http://example.com/" line: 0}]
[task 2021-12-20T22:47:04.165Z] 22:47:04     INFO - GECKO(2249) | Saw state c0010 and status 0
[task 2021-12-20T22:47:04.166Z] 22:47:04     INFO - GECKO(2249) | Browser got expected state change http://example.com/
[task 2021-12-20T22:47:04.312Z] 22:47:04     INFO - TEST-PASS | browser/components/urlbar/tests/browser/browser_stop_pending.js | Should not revert URL bar value! - 
```