Closed Bug 1525484 Opened 7 months ago Closed 7 months ago

React events with undefined handlers can break the markup view


(DevTools :: Inspector, defect, P2)

65 Branch


(firefox67 fixed)

Firefox 67
Tracking Status
firefox67 --- fixed


(Reporter: karlcow, Assigned: miker)


(Blocks 1 open bug)



(3 files)

So this one is strange.

Steps to reproduce:

  1. Go to
  2. Inspect Element with contextual menu on "Sort by:" for example

Open devtools at the right position in the inspector.

open the inspector with the body selected.
If I try to manually go to the right place, I can't find it. Only a parent is visible in the inspector see screenshot.

But if I copy outer HTML on this node.
and paste this into a code editor I get the right markup.

Mike, this issue seems to have similar symptoms as Bug 1524005, Bug 1522273 and similar ones you fixed lately. Can you please have a look if this is another case that needs to be captured?

Flags: needinfo?(mratcliffe)
Assignee: nobody → mratcliffe
Has STR: --- → yes
Flags: needinfo?(mratcliffe)
OS: Unspecified → All
Hardware: Unspecified → All
Priority: -- → P2

This is happening on Duolingo site too. :/
This is super inconvenient for diagnosing issues, given the number of react websites these days.

There is no sort by that I can see at

At the same time there is an issue on

Adding a screenshot of the page with sort by

Flags: needinfo?(mratcliffe) have completely different products, websites and website technologies depending on which country you are in.

Because I am UK based and they have no UK website I was forced onto the french version, which doesn't have this issue. Incidentally, even using a US VPN didn't prevent me being redirected to the French website, just saying.

After some experimentation I finally created a link that takes me to some products on the website you attached in your screenshot.

So just to clarify that the following websites have issues:

Flags: needinfo?(mratcliffe)
Summary: inspector doesn't show the DOM node, even if it exists → React events with undefined handlers can break the markup view
Pushed by
React events with undefined handlers can break the markup view r=pbro
Closed: 7 months ago
Resolution: --- → FIXED
Target Milestone: --- → Firefox 67
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