Opened 3 years ago

Last modified 2 years ago

#6113 closed defect

[webextension] Error when using block element in Firefox 50/51 — at Version 2

Reported by: Ross Assignee:
Priority: P2 Milestone: Adblock-Plus-3.0.3-for-Chrome-Opera-Firefox
Module: Platform Keywords:
Cc: trev, sebastian, kzar, greiner Blocked By:
Blocking: Platform: Firefox
Ready: yes Confidential: no
Tester: Ross Verified working: yes
Review URL(s):

Description (last modified by kzar)


Firefox 50 / 51 / Windows 7

Does not occur on Firefox 52+.

How to reproduce

  1. Have the Firefox Console open.
  2. Navigate to a website (any).
  3. Select [ABP Icon] > [Block element] > Select any element.

Observed behaviour

Often a filter will not be suggested and if the user cancels the dialog, the highlight overlays/styles on the page are not removed. The following error also appears in the console:

TypeError: window.tabs is undefined adblockplus.js:2261:13

Expected behaviour

Block element dialog to be functional, highlights removed if canceled, error not to occur.


  • This is caused by the let popupPageId = window.tabs[0].id; line in lib/filtercomposer.js, it turns out that window doesn't have a tabs property at all on Firefox 50.
  • This is not a regression since the last release, I can also reproduce with Adblock Plus 3.0.

Change History (2)

comment:1 Changed 3 years ago by kzar

  • Component changed from Unknown to Platform

comment:2 Changed 3 years ago by kzar

  • Description modified (diff)
  • Priority changed from Unknown to P2
  • Ready set

This isn't a regression since the 3.0 release so it's not a release blocker for 3.0.2.

I think we're going to have to consider increasing the minimum supported version of Firefox soon. The WebExtension API is buggy anyway, but in these older versions it's even worse. Options page is broken (#5971), apparently the devenv automatic reload feature doesn't work, block element is broken... probably other stuff too.

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