See https://bugzilla.mozilla.org/show_bug.cgi?id=1513459#c9 and https://bugzilla.mozilla.org/show_bug.cgi?id=1513459#c10

In practice the code at https://searchfox.org/mozilla-central/rev/25d5a4443a7e13cfa58eff38f1faa5e69f0b170f/browser/components/urlbar/UrlbarProviderSearchSuggestions.jsm#447-456 should not be executed if maxHistoricalSearchSuggestions is set to 0, since that is an opt-out mechanism.

[Tracking Requested - why for this release]: Users can't opt-out of historical search suggestions in the urlbar.

Self-reminder to request uplift once this is on m-c

https://hg.mozilla.org/mozilla-central/rev/5edc54d87ce8

Comment on attachment 9183307 [details]
Bug 1672643 - Do not show form history (search suggestions from history) at all when browser.urlbar.maxHistoricalSearchSuggestions == 0.

Beta/Release Uplift Approval Request

• User impact if declined: This fixes a regression where the user is not able to opt out of search suggestions from history.
• Is this code covered by automated tests?: Yes
• Has the fix been verified in Nightly?: No
• Needs manual test from QE?: Yes
• If yes, steps to reproduce: 1. New profile

2. Type test1 in the urlbar and press enter
3. Type test2 in the urlbar and press enter
4. Type test3 in the urlbar and press enter
5. Set browser.urlbar.maxHistoricalSearchSuggestions = 0
6. Type test in the urlbar. None of the previous test searches should appear as suggestions in the results. Note that I'm referring to results with the clock icon. I'm not referring to the search results pages in history with the default engine's favicon, which may appear.
7. Type a space then type test again, and repeat until there are no more suggestions from the default search engine. None of the previous test searches should appear.

• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): One-line change, well understood, has tests.
• String changes made/needed:

Comment on attachment 9183307 [details]
Bug 1672643 - Do not show form history (search suggestions from history) at all when browser.urlbar.maxHistoricalSearchSuggestions == 0.

No regression on nightly since it landed and the change is small, uplift approved for 83 beta 5, thanks.

https://hg.mozilla.org/releases/mozilla-beta/rev/0e0248590ac4

Hi,
I was able to reproduce this bug on Windows 10 on 83.0a1 (2020-09-27) (64-bit) (to make sure that I was able to see the bug) and then I verified on FF Nightly 84.0a1 (2020-10-30) (64-bit) and Beta 83.0b6 (64-bit) that the bug has been fixed.

Regards, Flor.