1188912 - [e10s] calling .focus() on an input field via cpows causes firefox to hang.

Status: RESOLVED WORKSFORME

(Firefox :: Extension Compatibility, defect, P2)

Description

[Jack Moffitt [:jack]]

With e10s and multiple content processes, recently Nightlies have started locking up when using Lastpass. I've seen this on both chase.com and allstate.com. The whole browser locks up completely and must be force killed at the command line.

Steps to reproduce:

1. Visit a site where a lastpass login is stored
2. Use the toolbar button menu to select "Show Matching Sites" and find the site and select "Autofill".
3. Cry.

Other menu items seem to be fine, but this one seems to reliably cause a lockup.

Comment 1

[Jorge Villalobos [:jorgev] (he/him)]

Could be related to bug 1008768, but I'm not sure.

Comment 2

[Andrew Zitnay]

I can reproduce, but only with e10s enabled.  Did something change with CPOWs recently?

In general, if you have e10s turned on, I'd recommend using our experimental e10s build:

https://rodan.lastpass.com/dev/lp_e10s.xpi

Comment 3

[Brad Lassey [:blassey] (use needinfo?)]

Jack, could you test with the e10s build of lastpass?

Comment 4

[Jack Moffitt [:jack]]

I was not aware there was such a thing. Indeed it seems to fix the problem.

Comment 6

[Andrew Zitnay]

FYI, I traced this freezing to calling focus() on an input field.  It definitely seems like a CPOW bug in Firefox.

Comment 7

[Mark Hammond [:markh] [:mhammond]]

This isn't lastpass specific. To reproduce, in Nightly open google.com and execute the following in a browser toolbox console:

> gBrowser.selectedBrowser.contentDocumentAsCPOW.getElementById("lst-ib").focus()

(note "lst-ib" is the id of the search field on google). The browser hangs and doesn't come back. Andrew tells me his most recent e10s compatible version of the LastPass addon no longer calls .focus() due to this - which is why the problem seems to go away with that latest installed, but the underlying problem remains.

Comment 8

[Andrew Zitnay]

(In reply to Mark Hammond [:markh] from comment #7)
> Andrew tells me his most recent e10s compatible
> version of the LastPass addon no longer calls .focus() due to this - which
> is why the problem seems to go away with that latest installed, but the
> underlying problem remains.

Just to clarify, the e10s build of LastPass (based on the add-on SDK) never relied on CPOWs in the first place.

I've updated our current production build of LastPass (which does rely on CPOWs) to not call focus() in the autofill case for our next release.  If this bug is fixed, I'll revert that change.

Comment 9

[Brad Lassey [:blassey] (use needinfo?)]

NI to tracy to confirm that this is multicontent process only

Comment 10

[Mark Hammond [:markh] [:mhammond]]

(In reply to Brad Lassey [:blassey] (use needinfo?) from comment #9)
> NI to tracy to confirm that this is multicontent process only

I can confirm that this is only with e10s enabled - comment 7 works as expected with e10s disabled.

Comment 11

[Tracy Walker [:tracy]]

Thanks Mark. I was NI'd to determine if dom.ipc.processCount is in play.  Do you have it set to the default of 1 or something greater than that?  If the latter, please reset it to 1, then see if this is reproducible.  Thanks again.

Comment 12

[Mark Hammond [:markh] [:mhammond]]

(In reply to [:tracy] Tracy Walker - QA Mentor from comment #11)
> Thanks Mark. I was NI'd to determine if dom.ipc.processCount is in play.  Do
> you have it set to the default of 1 or something greater than that?  If the
> latter, please reset it to 1, then see if this is reproducible.  Thanks
> again.

This happens when that pref is set to the default of 1.

Comment 13

[Jim Mathies [:jimm]]

Attachment: stacks

Comment 14

[Jim Mathies [:jimm]]

clearing this so it lands in triage.

Comment 15

[:shell escalante]

based on comment 7 - sounds like not a huge deal anymore and we haven't seen more reports of this impacting add-ons.  please untriage if you disagree

Comment 16

[Bill McCloskey [inactive unless it's an emergency] (:billm)]

I'm going to close this WORKSFORME. Mark's STR doesn't cause a hang for me. A lot of CPOW bugs got fixed six months ago or so. Hopefully this one did too.