User Agent: Mozilla/5.0 (Windows NT 5.1; rv:52.0) Gecko/20100101 Firefox/52.0 Build ID: 20170417065206 Steps to reproduce: Type something in the search bar, select a suggestion so it is highlighted, optionally select some text in the search bar, quickly press backspace and then enter. Actual results: Backspace is ignored, the highlighted suggestion is searched. Expected results: Selected text or a character before the cursor is deleted, the corrected query is searched.

[bugday-20170424] When I tried to reproduce this issue by pressing backspace, selected text or a character before the cursor is deleted from search bar, the edited query is searched and got proper result in latest Nightly. BROWSER: Firefox nightly 55.0a1/64-bit/ Build ID:20170424030211 OS: Windows 10.0/64-bit Need more information to reproduce: Does this happens in latest version of the browser? Does it happens in private tab? May be MAC OS is affected with this issue. Will be good to have a test-case regarding this issue to reproduce further!!

Selected text may appear deleted for a moment, but then it is back after pressing enter. You have to press enter immediately after backspace: the faster it is, the more chance of reproduce. I believe this is a race condition, try to do it in a slow virtual machine. I've checked in Nightly, it is reproducible. Nightly 55.0a1/32-bit/20170424030211. This is actually a regression, in version 50 it seems to work OK, in 51 it is broken.

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:55.0) Gecko/20100101 Firefox/55.0 I have tested this issue on Windows 10 x64 with the latest Firefox release (53.0) and the latest Nightly (55.0a1-20170426030329) and managed to reproduce it. After typing anything in the search bar and pressing the down arrow in order to select a suggestion, if quickly pressing the backspace and the enter key afterwards, the backspace is ignored and the highlighted suggestion is searched. I've performed a regression, here is the pushlog: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=7452437b3ab571b1d60aed4e973d82a1471f72b2&tochange=a71215ad8ab820b2310f5dd38fcfded38d18768b Taking in consideration the pushlog above, I think that Bug 1306639 seems the most possible candidate to have introduced the regression. Marco can you please take a look at this? Thank you.

The only possibility that's the cause, is that it's due to the change in the autocompletecontroller https://hg.mozilla.org/releases/mozilla-aurora/diff/e97d9eb2849a/toolkit/components/autocomplete/nsAutoCompleteController.cpp other code is unrelated with the search bar. Adding to our triage.

52 ESR is also affected.

Too late for 53, but we could still take a patch in 54.

I've found out that this bug is even more annoying than it seemed at the first glance: it happens not only immediately after backspace, but I can enter a whole new word after that, and if the suggestion didn't disappear at the moment I press Enter, the uncorrected query is searched.

Marked as backlog, marking fix-optional for 54.