1515802 - Intermittent browser/components/extensions/test/browser/browser_ext_contextMenus.js | Uncaught exception - at chrome://mochikit/content/tests/SimpleTest/EventUtils.js:507 - TypeError: aTarget is null

Status: RESOLVED DUPLICATE of bug 1515810

(WebExtensions :: Untriaged, defect, P5)

Description

[Treeherder Bug Filer]

Filed by: nbeleuzu [at] mozilla.com

https://treeherder.mozilla.org/logviewer.html#?job_id=218223766&repo=autoland

https://queue.taskcluster.net/v1/task/Mh5cKs0UR2SFdqP5uQ1eeA/runs/0/artifacts/public/logs/live_backing.log

14:03:25     INFO - TEST-PASS | browser/components/extensions/test/browser/browser_ext_contextMenus.js | menu item gamma found - 
14:03:25     INFO - Leaving test bound testRemoveAllWithTwoExtensions
14:03:25     INFO - Entering test bound test_bookmark_contextmenu
14:03:25     INFO - Console message: [JavaScript Warning: "Password fields present on an insecure (http://) page. This is a security risk that allows user login credentials to be stolen." {file: "http://mochi.test:8888/browser/browser/components/extensions/test/browser/context.html" line: 0 column: 0 source: "0"}]
14:03:25     INFO - Buffered messages logged at 14:03:25
14:03:25     INFO - Global property added while loading chrome://browser/content/places/browserPlacesViews.js: PlacesViewBase
14:03:25     INFO - Extension loaded
14:03:25     INFO - Console message: Warning: attempting to write 8033 bytes to preference extensions.webextensions.uuids. This is bad for general performance and memory usage. Such an amount of data should rather be written to an external file. This preference will not be sent to any content processes.
14:03:25     INFO - Buffered messages finished
14:03:25     INFO - TEST-UNEXPECTED-FAIL | browser/components/extensions/test/browser/browser_ext_contextMenus.js | Uncaught exception - at chrome://mochikit/content/tests/SimpleTest/EventUtils.js:507 - TypeError: aTarget is null
14:03:25     INFO - Stack trace:
14:03:25     INFO - synthesizeMouseAtCenter@chrome://mochikit/content/tests/SimpleTest/EventUtils.js:507:7
14:03:25     INFO - openChromeContextMenu@chrome://mochitests/content/browser/browser/components/extensions/test/browser/head.js:401:3
14:03:25     INFO - async*test_bookmark_contextmenu@chrome://mochitests/content/browser/browser/components/extensions/test/browser/browser_ext_contextMenus.js:561:20
14:03:25     INFO - Async*Tester_execTest/<@chrome://mochikit/content/browser-test.js:1106:34
14:03:25     INFO - async*Tester_execTest@chrome://mochikit/content/browser-test.js:1097:16
14:03:25     INFO - nextTest/<@chrome://mochikit/content/browser-test.js:995:9
14:03:25     INFO - focusedOrLoaded/<@chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:803:59
14:03:25     INFO - Leaving test bound test_bookmark_contextmenu
14:03:25     INFO - Entering test bound test_bookmark_context_requires_permission
14:03:25     INFO - Extension loaded
14:03:25     INFO - Console message: Warning: attempting to write 8113 bytes to preference extensions.webextensions.uuids. This is bad for general performance and memory usage. Such an amount of data should rather be written to an external file. This preference will not be sent to any content processes.
14:04:01     INFO - Not taking screenshot here: see the one that was previously logged

Comment 1

[Intermittent Failures Robot]

1 failures in 2648 pushes (0.0 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:
* autoland: 1

Platform breakdown:
* osx-10-10: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures.html#/bugdetails?bug=1515802&startday=2018-12-17&endday=2018-12-23&tree=all

Comment 2

[Intermittent Failures Robot]

2 failures in 1008 pushes (0.002 failures/push) were associated with this bug in the last 7 days.

Repository breakdown:
* mozilla-inbound: 1
* mozilla-central: 1

Platform breakdown:
* osx-10-10: 1
* macosx64-nightly: 1

For more details, see:
https://treeherder.mozilla.org/intermittent-failures.html#/bugdetails?bug=1515802&startday=2018-12-24&endday=2018-12-30&tree=all

Comment 3

[Rob Wu [:robwu]]

I was able to trigger this error when I artificially removed the delay between showing the bookmarks bar and opening a menu; i.e. removing the code between these blocks: https://searchfox.org/mozilla-central/rev/c43240cef5829b8a2dec118faff8a5e1fec6ae1b/browser/components/extensions/test/browser/browser_ext_contextMenus.js#520-521,561-563

Minimal test case:

add_task(async function open_bookmark_menu() {
  await PlacesUtils.bookmarks.insert({
    parentGuid: "toolbar_____",
    url: "https://example.com/",
    title: "Example"});

  const bookmarksToolbar = document.getElementById("PersonalToolbar");
  setToolbarVisibility(bookmarksToolbar, true);

  await openChromeContextMenu(
    "placesContext",
    "#PersonalToolbar .bookmark-item:last-child"); // Error here.
  closeChromeContextMenu("placesContext");

  setToolbarVisibility(bookmarksToolbar, false);
});

When I apply the patch for bug 1515810 to the above reproduction case, the error does not occur any more. Hence I'm marking this as a duplicate of bug 1515810.