Opened on 07/19/2016 at 12:13:18 PM

Closed on 07/19/2016 at 04:24:34 PM

Last modified on 08/26/2016 at 10:03:07 AM

#4251 closed defect (fixed)

Adblock Plus hangs trying to apply element hiding rules to blocked frames

Reported by: mapx Assignee: trev
Priority: P1 Milestone: Adblock-Plus-2.8-for-Firefox
Module: Adblock-Plus-for-Firefox Keywords:
Cc: trev, greiner Blocked By:
Blocking: #4211 Platform: Firefox
Ready: yes Confidential: no
Tester: Ross Verified working: yes
Review URL(s):

Description (last modified by trev)


windows 7 / 10
FF 48.0b7
ABP dev build

How to reproduce

  1. Go to
  2. Wait a bit and check the CPU usage.
  3. Close Firefox.

Expected results

CPU usage is low after the page is loaded, Firefox shuts down correctly.

Actual results

High CPU usage, Firefox hangs instead of shutting down.


This seems to be triggered by us blocking the frame. On this particular page the AddThis frame is blocked. Consequently, its contents don't load - the document remains in the "uninitialized" state forever which causes an infinite loop with the changes from #4211.

Attachments (0)

Change History (14)

comment:1 Changed on 07/19/2016 at 01:12:34 PM by mapx

  • Description modified (diff)

comment:2 Changed on 07/19/2016 at 01:14:11 PM by mapx

  • Description modified (diff)
  • Summary changed from high CPU usage dev build to (high CPU usage) + (crash on closing FF) dev build

comment:3 Changed on 07/19/2016 at 01:15:04 PM by mapx

  • Description modified (diff)

comment:4 Changed on 07/19/2016 at 01:24:41 PM by trev

Which website are we talking about? I guess that it is some Google search page with Acceptable Ads disabled?

comment:5 Changed on 07/19/2016 at 01:31:13 PM by mapx

it's but it does not matter: every site will generate the same behaviour
acceptable ads disabled

Last edited on 07/19/2016 at 01:31:42 PM by mapx

comment:6 Changed on 07/19/2016 at 01:35:09 PM by mapx

well, not every site ... but if the behaviour starts on for example ... but changing the page the high cpu usage will still remain ON

comment:7 Changed on 07/19/2016 at 01:37:21 PM by trev

  • Blocking 4211 added
  • Description modified (diff)
  • Priority changed from Unknown to P1
  • Ready set

Never mind, I was able to reproduce this behavior so I see the problem...

comment:8 Changed on 07/19/2016 at 02:33:47 PM by trev

  • Description modified (diff)

comment:9 Changed on 07/19/2016 at 03:06:53 PM by trev

  • Summary changed from (high CPU usage) + (crash on closing FF) dev build to Adblock Plus hangs trying to apply element hiding rules to blocked frames

comment:10 Changed on 07/19/2016 at 04:19:58 PM by trev

  • Owner set to trev

comment:11 Changed on 07/19/2016 at 04:20:11 PM by trev

  • Review URL(s) modified (diff)
  • Status changed from new to reviewing

comment:12 Changed on 07/19/2016 at 04:23:49 PM by abpbot

comment:13 Changed on 07/19/2016 at 04:24:34 PM by trev

  • Milestone set to Adblock-Plus-for-Firefox-next
  • Resolution set to fixed
  • Status changed from reviewing to closed

comment:14 Changed on 08/26/2016 at 10:03:07 AM by Ross

  • Tester changed from Unknown to Ross
  • Verified working set

CPU usage no longer looks excessive and Firefox shuts down correctly.

Firefox 38 / 45 / 49.0b1 / Windows 7

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