Open Bug 1445152 Opened 3 years ago Updated 10 months ago

Drop HAR files here: Network Monitor


(DevTools :: Netmonitor, defect, P3)

61 Branch


(Not tracked)


(Reporter: deejtonks, Unassigned)


(Blocks 1 open bug)



(1 file)

Attached image HAR files.png
User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0
Build ID: 20180312134431

Steps to reproduce:

I was dragging an image file over to Discord, I might've hovered over the Network Monitoring tab, and the "Drop HAR files here" will not go away even after refreshing the page. It's only the tab that I was on that does it which means if I close the tab it'll probably go away. It's only on the "Network" section, all other sections are fine.

Actual results:

"Drop HAR files here" -> I can still do other things though.

Expected results:

It should of showed "Drop HAR files here" until the file was no longer hovered over it.
Additional information: you must go on/off the Network Monitor tab with the file being dragged quite fast for it to happen.
Component: Untriaged → Developer Tools: Netmonitor
Thanks for the report!

Unfortunately I can't reproduce it on my machine (Win10 64). I am trying to drag one or more files, quickly, slowly, different file types, but the "Drop HAR files here" always goes away when the mouse leaves the Network panel area. Is there anything special I should do? What could be different between our configs?

Priority: -- → P3
Ok, I was able to repro it now.

Here is my STR
1) Ope the Toolbox select the Network panel
2) Reload the page, so there are some requests
3) Select a request, so the side bar opens
4) Select The Headers tab (should be selected by default)
5) Drag a file onto Header tab content area (do not release the mouse)
6) Now, move quickly out of the area -> The "Drop HAR files here" stays there. I am able to repro relatively easily if moving up towards the web page content.

I am not saying the issue is related to the Headers panel, but from some reason it's easier to repro that.

It could also be platform issue.

(In reply to Jan Honza Odvarko [:Honza] from comment #3)
> It could also be platform issue.
More info to this:

The core issue is that the "onDragExit" event isn't sent sometimes:

@Vladimir, could this be a platform issue? (see comment #4)

(not sure who should I ask for more analysis)

Flags: needinfo?(vladimir)
@Neil, maybe you know more? (see comment #4)

Any reason why "onDragExit" event would be missing?

Flags: needinfo?(enndeakin)
Is this a dragexit event that gets lost when dragging from the chrome area to the child process window? Does it happen only on Windows?
Flags: needinfo?(enndeakin)
Ever confirmed: true
(In reply to Neil Deakin from comment #7)
> Is this a dragexit event that gets lost when dragging from the chrome area
> to the child process window?
Yes, it seems to be the problem (at least that's what my experimentation in comment #3 indicates).

> Does it happen only on Windows?
I was trying to reproduce it on my MacBook, but no luck,
so might be Win issue only.

Flags: needinfo?(enndeakin)
In that case, it may be similar to 1256162, so it would be worth investigating the code in EventStateManager::HandleCrossProcessEvent that was changed for that bug.

Otherwise, dragexit is sent by EventStateManager::GenerateDragDropEnterExit
Flags: needinfo?(enndeakin)
This symptom happened several times over a short debugging session for me as of yesterday.

My current user agent is Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:61.0) Gecko/20100101 Firefox/61.0 but an update was applied when I just launched today.

I am someone who frequently highlights text to read it, including within the developer tools themselves, so a drag/drop issue sees related, but these reproduction steps don't work for me as of today's build.

I can't find a newer related bug, did this bug regress and fix in the daily developer edition builds?
Product: Firefox → DevTools
Flags: needinfo?(vladimir)
I find that I can work around this bug by dragging a file over the network panel and then slowly dragging it out.
You need to log in before you can comment on or make changes to this bug.