1597946 - Browser debugger goes blank

Status: RESOLVED FIXED

(DevTools :: Debugger, defect, P1)

Description

[Jan Honza Odvarko [:Honza] (always need-info? me)]

This happened to me today when debugging MQTT WS payload

STR:

1. Download and apply this patch: https://phabricator.services.mozilla.com/D41445
2. Build and Run Firefox
3. Open DevTools & Network panel on http://rtsdp.eu5.org/dashboard/TestMosquittoOrgDashboard.html
4. You should see WS 101 HTTP request in the list, select it and go to the Messages panel - Do not select any frame yet
5. Open the Browser Debugger and create BP in netmonitor/src/components/websockets/FramePayload.js on line 159 (it should be where const decoder = MQTTDecoder(); ctor is called.
6. Select a WS frame in the Messages panel
7. The BP should hit. Hover over the MQTTDecoder(); ctor to see a preview -> the entire browser debugger panel goes blank

Honza

Comment 1

[Jan Honza Odvarko [:Honza] (always need-info? me)]

Jason, can you reproduce that?
Can you please investigate this ASAP?

Honza

Comment 2

[Jason Laster [:jlast]]

Looking into it

Comment 3

[Jason Laster [:jlast]]

Thanks for sharing.

This is failing because we're trying to create a rep with an empty array of roots. Rep({ object: result }) in Popup.js. The issue is that shouldRenderRootsInReps check crashes when doing this check.

One simple fix would be to change the roots length check at the top to if (roots.length !== 1).

Comment 4

[Jason Laster [:jlast]]

Attachment: Bug 1597946 - Browser debugger goes blank. r=nchevobbe

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/8127325c6941
Browser debugger goes blank. r=nchevobbe

Comment 6

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/8127325c6941