We stopped using this preference in bug 1029148 for Firefox 34. In bug 1405670 we dropped migration code for search settings written before Firefox 45; we should have removed this pref migration code too.

Simple code removal. The only other reference to this pref in our code is the test at https://searchfox.org/mozilla-central/rev/f5f1c3f294f89cfd242c3af9eb2c40d19d5e04e7/toolkit/components/search/tests/xpcshell/test_selectedEngine.js#16 that actually verifies that the pref has no effect anymore.

Pushed by florian@queze.net: https://hg.mozilla.org/integration/mozilla-inbound/rev/9a7bc6776fb7 Stop migrating the browser.search.selectedEngine preference, r=adw.

Comment on attachment 8935861 [details] [diff] [review] Patch Approval Request Comment [Feature/Bug causing the regression]: Not a regression, just something I missed in bug 1405670. [User impact if declined]: Slight risk of abuse for an old preference to change the user's default search engine. [Is this code covered by automated tests?]: no. [Has the fix been verified in Nightly?]: no. [Needs manual test from QE? If yes, steps to reproduce]: no. [List of other uplifts needed for the feature/fix]: none [Is the change risky?]: The risk is almost non-existant [Why is the change risky/not risky?]: Only removing some dead migration code that has stayed in the tree for far longer than initially expected. [String changes made/needed]: none.

Comment on attachment 8935861 [details] [diff] [review] Patch Take this for follow-up of bug 1405670. Beta58+.