1401454 - Focusing on input element causes: leakcheck | default process: 8 bytes leaked (nsStringBuffer)

Status: RESOLVED WORKSFORME

(Core :: DOM: UI Events & Focus Handling, enhancement, P2)

Description

[Ray Lin[:ralin]]

Split off the memory leak problem from bug 1393374.

A reduced test case mentioned in: https://bugzilla.mozilla.org/show_bug.cgi?id=1393374#c16, which only run .focus() on an input element cause the memory leaked. We no idea why would be this case since it seems unreasonable.

TH results:
with focus - [leaked]
https://treeherder.mozilla.org/#/jobs?repo=try&revision=e1f24ba39a993052cc9828849d587fbe4d914082

without focus - [no leak]
https://treeherder.mozilla.org/#/jobs?repo=try&revision=8bbc850f799f6e4d17819c3dbfa4b4c69a715b67

Also we've commented out our focus listener in frameScript, so it should has nothing to do with form autofill.

Comment 1

[Hsin-Yi Tsai (she/her) [:hsinyi]]

Olli, could you please take a look?

Comment 2

[Olli Pettay [:smaug][[e-mail]]]

Ray, could you explain what is the minimal test case for this?
And does this happen on OSX only? (Usually I have access to Linux only)

data:text/html,<input autofocus> doesn't seem to leak, nor
data:text/html,<input> with manual focusing, nor
data:text/html,<script>onload = function() { document.getElementsByTagName("input")[0].focus(); }</script><input>

Comment 3

[Olli Pettay [:smaug][[e-mail]]]

Actually, is this possibly Bug 1403026.

Comment 4

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

Yeah, probably. I already wrote a patch:
https://treeherder.mozilla.org/#/jobs?repo=try&revision=11917f47319f2a5c52b5c207effbcedb72581763&filter-tier=1

Comment 5

[Ray Lin[:ralin]]

Sorry for the late reply.

(In reply to Olli Pettay [:smaug] from comment #2)
> Ray, could you explain what is the minimal test case for this?
> And does this happen on OSX only? (Usually I have access to Linux only)
The test case is landed on m-c with skip-if=debug: http://searchfox.org/mozilla-central/rev/298033405057ca7aa5099153797467eceeaa08b5/browser/extensions/formautofill/test/mochitest/mochitest.ini#12-14, for verifying a serial of form auto-filling popup results with different type of fields.

The TH result this morning with skip-if=debug removed, and no leak was found:
https://treeherder.mozilla.org/#/jobs?repo=try&revision=c5516189608dd495b87e3c9a48e05f109bd1df32, maybe Bug 1403026 has fixed it. \o/

Not sure how to determine a the leak issue is resolved, but for our use case, .focus() seems no longer cause the leak. I guess it's fine to close this bug if no other concerns.

Comment 6

[Ray Lin[:ralin]]

Thanks for your help Olli, Masayuki :D

Comment 7

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)]

No problem, it was really my fault. I'm sorry.