Thank you for helping make Firefox better. If you are reporting a defect, please complete the following:

What were you doing?

I was working with the new event listener breakpoints in order to document them, using Firefox Developer edition, 69.0b13, 64-bit.

Please tell us what site you were on, and what steps led to the error you are reporting

Site is https://irenesmith.com/examples/stuff2do/
The application is a simple jQuery todo list that I created a couple of years ago when I was trying to learn jQuery.

1. Clicked in the add task description box, typed text for new task
2. Enabled click event listener breakpoint
3. Clicked the Add Task button

What happened?

When I clicked the AddTask button, execution ended up in onloadwff.js
There were no error messages and the browser did not crash

What, if any, error messages did you see? Did the browser crash? Screenshots or screen recordings can be attached to this report and are helpful in isolating and replicating the bug.

What should have happened?

I would have expected the code to pause within my event listener for AddTask click.

Was was the expected result? ("Not crashing" may be a valid answer.)

Anything else we should know?

Do you have extensions installed? You can also go to about:support in another window or tab and attach the report it generates to this bug.

Thank you for the report! Just to clarify, are you saying there was no pause, or the app paused in a place different than you had expected?

I followed the STR (in current Nightly) and the debugger paused in the jQuery file (https://code.jquery.com/jquery-3.1.1.min.js); I believe in the function that's responsible for jQuery's event handling logic.

Thank you for any additional info!

I would have been less surprised if it had paused in a jQuery file but when I ran it, it paused in onloadwff.js. So control did pause, just not in my code. I have another app that uses vanilla javascript. When I activate the click listener breakpoint, it also breaks in onloadwff.js. Is that the behavior it should have? This is still in the Developer version of 69.0b13. I can try it in Nightly later today and will report the results.

Looks like it's possible an extension collision; seems like Chrome users are having the same issue; https://github.com/lastpass/lastpass-cli/issues/428

onloadwff.js is an extension file (lastpass). Until we ignore extensions by default, this will happen for all pausing (exceptions, DOM, etc).

Shoot! I've been using LastPass so long I didn't even think of it. Thanks!

Closing this for now, as it pauses correctly in the extension.