Opened on 09/09/2015 at 09:42:56 PM

Closed on 11/10/2017 at 11:15:18 AM

#3046 closed defect (rejected)

Setting that enforces ABP to load completely at Firefox startup doesn't work

Reported by: tempuser1231 Assignee:
Priority: Unknown Milestone:
Module: Adblock-Plus-for-Firefox Keywords:
Cc: greiner, trev, mapx Blocked By:
Blocking: Platform: Firefox
Ready: no Confidential: no
Tester: Unknown Verified working: no
Review URL(s):


By design ABP lets Firefox start loading pages before ABP is fully loaded. The result is a race condition where restored browsing sessions sometimes contain ads. This is a security issue due to malware served through ad networks, and a privacy issue due to tracking. #549 introduced the misleading setting extensions.adblockplus.please_kill_startup_performance to force ABP to completely load before Firefox loads pages. Unfortunately it doesn't work.


Any versions of Firefox and ABP released since extensions.adblockplus.please_kill_startup_performance was introduced.

How to reproduce

  1. Configure Firefox to open the previous session on startup and enable extensions.adblockplus.please_kill_startup_performance in about:config
  2. Open some windows and tabs with web sites that normally contain ads
  3. Restart Firefox

Observed behaviour

Sometimes there are ads in parts of the restored session, as if extensions.adblockplus.please_kill_startup_performance was disabled. Unfortunately the issue can't be reproduced deterministically due to the nature of race conditions.

Expected behaviour

No ads in restored session, and by extension protection from malware and tracking.

Attachments (0)

Change History (3)

comment:1 Changed on 09/09/2015 at 09:47:43 PM by mapx

  • Cc greiner trev mapx added
  • Component changed from Unknown to Adblock-Plus-for-Firefox

comment:2 Changed on 09/09/2015 at 09:48:10 PM by mapx

  • Platform changed from Unknown / Cross platform to Firefox

comment:3 Changed on 11/10/2017 at 11:15:18 AM by trev

  • Resolution set to rejected
  • Status changed from new to closed

Mass-closing all bugs in Adblock Plus for Firefox module, the codebase of Adblock Plus 3.0 belongs into Platform and User-Interface modules. Old bugs are unlikely to still apply.

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