[Note] This is a follow-up bug for Bug 1257847 [Affected versions]: Firefox 49.0a1 (2016-05-12) Firefox 48.0a2 (2016-05-12) Firefox 47.0b4 (20160509171155) [Affected platforms]: Windows 10 64-bit Ubuntu 14.04 32-bit Mac OS X 10.9.5 [Steps to reproduce]: 1.Launch Firefox with clean profile. 2.Install the following add-on: https://addons.mozilla.org/en-US/firefox/addon/adblock-edge/?src=ss 3.Go to about:addons -> Extensions 4.Click on Adblock Edge “Options” button. 5.Select the "Show in toolbar" checkbox. [Expected results]: The Adblock Edge icon is successfully displayed in toolbar. [Actual results]: - The icon is not displayed. - The check mark is erased while refreshing the page. - “Filter preferences…” button does nothing. [Regression Range]: Last good revision: 2afd5728f13aebe9c2daa85dd831b4e4ac2ac121 First bad revision: 69a9775dc5c921d180a4fef1d2e7812610e70d56 Pushlog: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=2afd5728f13aebe9c2daa85dd831b4e4ac2ac121&tochange=69a9775dc5c921d180a4fef1d2e7812610e70d56

Which bug do you think that caused this regression?

One's just fixing our own code internally, so it's not that. Ergo, bug 1146136. Note that that change was a spec issue we had to fix, and it landed a very long time ago with basically no issues, so it's not going to be reverted or backed out. The addon should be updated according to the discussion of the change at <http://whereswalden.com/2015/06/20/new-changes-to-make-spidermonkeys-and-firefoxs-parsing-of-destructuring-patterns-more-spec-compliant/>.

Jorgev, could someone reach out to the addon author based on comment 2 please?

I sent a message to the developer. However, the add-on hasn't been updated for a while and the description says it is abandoned, so I don't know if it will be updated.

Marking as won't fix then. Thanks Jorge.