One results stability/predictability fix we added to the old Address Bar was to freeze the list of results when the user either changes the selection or mouseovers a different result (this is a bit more tricky considered the cursor may be in the popup area at popup opening, so I'm not sure we did this properly or at all in the old code)
We should probably do the same, because it's quite annoying when you aim at something and it changes just before you confirm it.

Note: When we implement this, please also re-enable browser_urlbarStopSearchOnSelection.js (remove skip-if) which has been ported, but obviously fails at the moment.

(In reply to Mark Banner (:standard8) from comment #1)

Note: When we implement this, please also re-enable browser_urlbarStopSearchOnSelection.js (remove skip-if) which has been ported, but obviously fails at the moment.

This test also depends on bug 1535656 so I filed bug 1539804 on this.

Backed out changeset 9eca658703d9 (bug 1524510) for browser chrome failures in browser/components/urlbar/tests/browser/browser_autoFill_preserve.js. CLOSED TREE

Log:
https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=236887861&repo=autoland&lineNumber=6760

INFO - TEST-START | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js
[task 2019-03-29T12:41:12.697Z] 12:41:12 INFO - GECKO(2825) | [Parent 2825, Main Thread] WARNING: Suboptimal indexes for the SQL statement 0x7fb606246b40 (http://mzl.la/1FuID0j).: file /builds/worker/workspace/build/src/storage/mozStoragePrivateHelpers.cpp, line 108
[task 2019-03-29T12:41:13.044Z] 12:41:13 INFO - GECKO(2825) | [Parent 2825, Main Thread] WARNING: NS_ENSURE_SUCCESS(rv, rv) failed with result 0x80040111: file /builds/worker/workspace/build/src/startupcache/StartupCacheUtils.cpp, line 157
[task 2019-03-29T12:41:13.080Z] 12:41:13 INFO - TEST-INFO | started process screentopng
[task 2019-03-29T12:41:13.664Z] 12:41:13 INFO - TEST-INFO | screentopng: exit 0
[task 2019-03-29T12:41:13.666Z] 12:41:13 INFO - Buffered messages logged at 12:41:12
[task 2019-03-29T12:41:13.666Z] 12:41:13 INFO - Entering test bound init
[task 2019-03-29T12:41:13.666Z] 12:41:13 INFO - Leaving test bound init
[task 2019-03-29T12:41:13.667Z] 12:41:13 INFO - Entering test bound origin
[task 2019-03-29T12:41:13.667Z] 12:41:13 INFO - Buffered messages logged at 12:41:13
[task 2019-03-29T12:41:13.667Z] 12:41:13 INFO - TEST-PASS | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js | true == true -
[task 2019-03-29T12:41:13.667Z] 12:41:13 INFO - TEST-PASS | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js | "ExAmple.com/" == "ExAmple.com/" -
[task 2019-03-29T12:41:13.667Z] 12:41:13 INFO - TEST-PASS | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js | 3 == 3 -
[task 2019-03-29T12:41:13.668Z] 12:41:13 INFO - TEST-PASS | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js | 12 == 12 -
[task 2019-03-29T12:41:13.668Z] 12:41:13 INFO - TEST-PASS | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js | 1 == 1 -
[task 2019-03-29T12:41:13.668Z] 12:41:13 INFO - TEST-PASS | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js | "http://mozilla.org/example" == "http://mozilla.org/example" -
[task 2019-03-29T12:41:13.669Z] 12:41:13 INFO - Buffered messages finished
[task 2019-03-29T12:41:13.670Z] 12:41:13 INFO - TEST-UNEXPECTED-FAIL | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js | 0 == -1 - JS frame :: chrome://mochitests/content/browser/browser/components/urlbar/tests/browser/browser_autoFill_preserve.js :: checkKeys :: line 226
[task 2019-03-29T12:41:13.671Z] 12:41:13 INFO - Stack trace:
[task 2019-03-29T12:41:13.671Z] 12:41:13 INFO - chrome://mochitests/content/browser/browser/components/urlbar/tests/browser/browser_autoFill_preserve.js:checkKeys:226
[task 2019-03-29T12:41:13.672Z] 12:41:13 INFO - chrome://mochitests/content/browser/browser/components/urlbar/tests/browser/browser_autoFill_preserve.js:origin:31
[task 2019-03-29T12:41:13.672Z] 12:41:13 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest/<:1106
[task 2019-03-29T12:41:13.673Z] 12:41:13 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest:1134
[task 2019-03-29T12:41:13.673Z] 12:41:13 INFO - chrome://mochikit/content/browser-test.js:nextTest/<:995
[task 2019-03-29T12:41:13.674Z] 12:41:13 INFO - chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:SimpleTest.waitForFocus/waitForFocusInner/focusedOrLoaded/<:803
[task 2019-03-29T12:41:13.675Z] 12:41:13 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-03-29T12:41:13.676Z] 12:41:13 INFO - TEST-UNEXPECTED-FAIL | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js | "ExAmple.com/" == "ExA" - JS frame :: chrome://mochitests/content/browser/browser/components/urlbar/tests/browser/browser_autoFill_preserve.js :: checkKeys :: line 227
[task 2019-03-29T12:41:13.677Z] 12:41:13 INFO - Stack trace:
[task 2019-03-29T12:41:13.677Z] 12:41:13 INFO - chrome://mochitests/content/browser/browser/components/urlbar/tests/browser/browser_autoFill_preserve.js:checkKeys:227
[task 2019-03-29T12:41:13.678Z] 12:41:13 INFO - chrome://mochitests/content/browser/browser/components/urlbar/tests/browser/browser_autoFill_preserve.js:origin:31
[task 2019-03-29T12:41:13.678Z] 12:41:13 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest/<:1106
[task 2019-03-29T12:41:13.679Z] 12:41:13 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest:1134
[task 2019-03-29T12:41:13.679Z] 12:41:13 INFO - chrome://mochikit/content/browser-test.js:nextTest/<:995
[task 2019-03-29T12:41:13.680Z] 12:41:13 INFO - chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:SimpleTest.waitForFocus/waitForFocusInner/focusedOrLoaded/<:803
[task 2019-03-29T12:41:13.680Z] 12:41:13 INFO - TEST-PASS | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js | 1 == 1 -
[task 2019-03-29T12:41:13.682Z] 12:41:13 INFO - TEST-PASS | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js | "http://mozilla.org/example" == "http://mozilla.org/example" -
[task 2019-03-29T12:41:13.683Z] 12:41:13 INFO - TEST-PASS | browser/components/urlbar/tests/browser/browser_autoFill_preserve.js | 0 == 0 -

Push with failures:
https://treeherder.mozilla.org/#/jobs?repo=autoland&revision=9eca658703d92afe37923f313c9f662d16b98627

Backout:
https://hg.mozilla.org/integration/autoland/rev/6726a4f0b9420f70f5fa667e5083bb84a6ec0df2

https://hg.mozilla.org/mozilla-central/rev/a1cfb4874e27