(Unfortunately I don't have *reliable* STR for this bug, but I'm filing because I've been hitting it repeatedly and it's bad enough that it needs to be tracked somewhere.) STR for me (once a day or so): 1. Open a new tab with Ctrl T. 2. Start typing a search term to filter your awesomebar history. (E.g. I just started typing "dev platform" ACTUAL RESULTS: Around once per day, my typing will be interrupted and I will be navigated to a Google search page for my partially-entered text. E.g. in this case (when I was typing "dev platform", all of a sudden I ended up at https://www.google.com/search?q=dev+pl&ie=utf-8&oe=utf-8 (a search page for "dev pl") It seems like the location bar is synthesizing a phantom "enter" keypress, or the equivalent, at some point during my text entry. NOTES: This happens to me once every day or so, it seems like. When it happens, my system is usually loaded down (via a compile job running in the background), and I've usually just re-focused my Firefox window after it having been un-focused for a few minutes. I'm using Nightly 51.0a1 (2016-08-13) with e10s disabled, and I have a bunch of add-ons installed & enabled, in case they happen to be involved: Version Enabled ID ADB Helper 0.8.7 true adbhelper@mozilla.org Adblock Plus 2.7.3 true {d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d} BrowserStack 23.1 true {6cc0f0f7-a6e2-4834-9682-24de2229b51e} CSS Grid Visualizer 1.2.0 true @gridviz FlyWeb 1.0.0 true flyweb@mozilla.org FoxyProxy Basic 3.5.6 true foxyproxy-basic@eric.h.jung Google search link fix 1.5.3 true jid0-XWJxt5VvCXkKzQK99PhZqAn7Xbg@jetpack HTTPS-Everywhere 5.2.1 true https-everywhere-eff@eff.org Mass Password Reset 1.05.1-signed.1-signed true masspasswordreset@johnathan.nightingale Mozilla Tree Status 1.0.2 true mozilla-tree-status@jsantell.com Multi-process staged rollout 1.0 true e10srollout@mozilla.org MXR to DXR 0.2.2 true jid1-4pnKlU8xM5edbw@jetpack Noments 0.1.0 true @noments NoScript 2.9.0.14rc1 true {73a6fe31-595d-460b-a920-fcc0f8843232} Pocket 1.0.4 true firefox@getpocket.com RefControl 0.8.17.1-signed.1-signed true {455D905A-D37C-4643-A9E2-F6FEFAA0424A} Send to Kindle for Mozilla Firefox 1.0.2.76 true sendtokindle@amazon.com Stylish 2.0.7 true {46551EC9-40F0-4e47-8E18-8E5CF550CFB8} Twitter Link Expander 1.0.0 true jid1-DwRap1pOaj8qgQ@jetpack User Agent Overrider 0.4.1 true useragentoverrider@qixinglu.com