Open Bug 1549304 Opened 7 months ago Updated 7 months ago

focusout event is not reliable under certain circumstances


(DevTools :: Debugger, defect, P3)

68 Branch


(firefox67 affected, firefox68 affected)

Tracking Status
firefox67 --- affected
firefox68 --- affected


(Reporter: artemz, Unassigned)


(Blocks 1 open bug)



(2 files)

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73.0.3683.103 Safari/537.36

Steps to reproduce:

Open this url:, observe Success header displayed in green. Open the debugger, reload the page via cmd + R

Actual results:

You'll see Fail statement painted red.

Expected results:

I'd expect the behaviour to remain in the debugger mode, i.e. the message on the page should be Success. This happens because of inconsistent firing of the 'focusout' event for the input. This doesn't happen in Safari. A similar behaviour is observed in Chrome however the scenario is a bit more complicated.

Hi Artem,

I tested the reported issue on the latest Firefox Nightly version (68.0a1), using both Mac OSX 10.14 and Windows 10, and I got the following behavior:

  1. I open the url , see the Success header in green.
  2. Open the debugger
  3. Reload page

As a result, I don't see any fail statement, in my case the page is infinite loading, noting is displayed in the browser. (see screenshot attached on the next message). Is this the actual result you are getting on your end?

Please test this by using the latest Firefox Nightly and share your result with us. You can download it from here:

Thank you for your report.

Flags: needinfo?(artemz)
Attached image focusout.gif

Hi Virginia,

Thank you for your reply. You did everything right. I tried the scenario once again on the nightly build and noticed that the execution indeed (sometimes) pauses on a debugger statement (which is a part of another scenario that is relevant for Chrome). If you press Play while on Pause and reload the page afterwards via cmd + R, the issue will be in place. From what I noticed - the behaviour may depend on whether you click somewhere inside the html page before you reload it or not.

Flags: needinfo?(artemz)
Attached image focusout_artem.gif

Hi Artem,

You are right. It seems the behavior depends on whether you click somewhere inside the page (like the "Click" button). I was able to reproduce this on the following versions:

  • beta 67.0b19
  • release 67.0
  • Nightly 68.0a1 (2019-05-15)

I'll update the product and component so the developers can take a look at this.

Component: Untriaged → Debugger
Ever confirmed: true
Product: Firefox → DevTools
Blocks: dbg-control
Priority: -- → P3

Thanks, my guess is that the debugger is trying to focus on an element which is moving the focus away from the input. We'll look into it

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