Steps to Reproduce: 1. Open Nightly 2. Go to about:preferences#search 3. Click at "Find more search engines" 4. Select search engine and click at "Add to Firefox" button. Expected Result: The add-on is successfully installed and added to the list of available engines and is properly set as a default search engine. Actual Result: No response.

This issue is also reproducible on Mac OS X 10.14, Ubuntu 16.04. We also tested on Windows 7 and here the search engine is added but you are not prompted with the pop-up where you are informed that the add-on is added. This issue is not reproducible on FF Beta 64 and FF release 63, we did a regression window and here si the result: Last good revision: e20a3ab2ca2ca3326233cee26c2bed5c3c647e0e First bad revision: 7db2b627cacc8440f99ac86c266e858188da3d28 Pushlog: https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=e20a3ab2ca2ca3326233cee26c2bed5c3c647e0e&tochange=7db2b627cacc8440f99ac86c266e858188da3d28 Andrea, can you please take a look at this, the regression range points out one of your bugs? Thanks

Let's allow AMO to use AddSearchProvider

After discussion, we should flip the pref back for nightly as well until we have a better long term plan. We should also verify that the deprecation message is displaying. We should also communicate with the AMO and mycroft folks the longer term plan here.

(In reply to Mike Kaply [:mkaply] from comment #3) > After discussion, we should flip the pref back for nightly as well until we > have a better long term plan. > > We should also verify that the deprecation message is displaying. > > We should also communicate with the AMO and mycroft folks the longer term > plan here. Thanks

Deprecate AddSearchProvider and keep it enabled in nightly.

Comment on attachment 9031820 [details] [diff] [review] deprecate_addSearchProvider.patch Do we want to keep the UseCounter? Can we do both?

> Do we want to keep the UseCounter? Can we do both? We cannot. "Deprecated" implies "UseCounter".

Pushed by amarchesini@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/3c2aa0afce01 Deprecate AddSearchProvider, r=mkaply

Updated the site compatibility note: https://www.fxsitecompat.com/en-CA/docs/2018/window-sidebar-and-window-external-addsearchprovider-have-been-deprecated/

I have reproduced this bug with Nightly 65.0a1 (2018-12-04) on Windows 7, 64 Bit! This bug's fix is verified with latest Beta! Build ID 20181220174318 User Agent Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:65.0) Gecko/20100101 Firefox/65.0

Verified. Version 66.0a1 User Agent Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:66.0) Gecko/20100101 Firefox/66.0