User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:62.0) Gecko/20100101 Firefox/62.0 Build ID: 20180605220158 Steps to reproduce: Seen on Mozilla/5.0 (Macintosh; Intel Mac OS X 10.14; rv:62.0) Gecko/20100101 Firefox/62.0 running on OS X 10.14 beta 1 1. Launch Firefox with previous tabs opened 2. Switch to one of the tabs and click the down arrow 3. Switch to another tab and click the down arrow again Actual results: 1. In step (2) the dropdown menu appears, but not in step (3) 2. URL autocomplete is broken after the above step (3) Expected results: 1. Address dropdown should be shown. 2. URL autocomplete works

Add a video showing this bug

Following since I do see the URL autocomplete issue when using the browser.

I could reproduce this issue on Version 62.0a1 Build ID 20180611100116 User Agent Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:62.0) Gecko/20100101 Firefox/62.0

Adding affected branches. This is present in the second developer beta as well and is pretty annoying. For me, I don't think I actually performed the STR noted here, but I always have to open items in a new window in order to get the autocomplete to work.

It could also be related to the pointer-events trick, if we somehow fail to properly set/unset the open attribute. .urlbar-history-dropmarker[open] { pointer-events: none; } In particular the requestAnimationFrame in "popuphidden" could end up removing the attribute at the wrong time. Is this only reproducible on 10.14?

> Is this only reproducible on 10.14? I first _noticed_ the issue after installing 10.14 beta - so in my experience yes, but I could be wrong.

Just wanted to add the downloads dropdown does not show either (it's not only the address bar). Settings dropdown just worked a few time, and right now it does not anymore. 62.0b4 though.

This is definitely a Mojave-exclusive bug. I did not have this behavior in 10.13.4. Can confirm the behavior that Markus Doits noted on Nightly 63.0a1. Seems this affects all branches when user is on 10.14. I am now on the Public Beta and this issue is persistent. I've also noticed that the autocomplete on the address bar breaks intermittently as well and having autocomplete and address bar dropdown not working is awful. It's a total workflow wrecker.

Confirm. Same situation on Mojave public beta

[Tracking Requested - why for this release]: 10.14 release this fall

Fx62 should be out before 10.14, so tracking seems more appropriate for that release. That said, I'd be willing to consider a low-risk patch as a dot release ride-along should one be available.

Taking conversation to bug 1468053 as it has the most information. I don't seem to be able to copy the tracking flags however. RyanVM, could you do so?