1855692 - When network change, Firefox appends extra bytes to the WebSocket message

Status: RESOLVED INVALID

(Core :: Networking: WebSockets, defect)

Description

[anton.kosyakov]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/117.0.0.0 Safari/537.36

Steps to reproduce:

• Open a workspace in gitpod.io using Firefox with VS Code Browser.
• Open DevTools and monitor WebSocket activity.
• Toggle your network (e.g., in my case, I changed the exit node of Tailscale).

Actual results:

Notice that the WebSocket connections are functional, but VS Code Browser becomes non-functional.

Further analysis reveals that unexpected extra bytes are sent to the server over the WebSocket, disrupting the communication, see https://github.com/microsoft/vscode/issues/194284#issuecomment-1738844034

Note: This issue is not observed when performing the same steps using Chromium based browsers.

Expected results:

VS Code should stay functional as it happens with Chrome.

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

The Bugbug bot thinks this bug should belong to the 'Core::Networking: WebSockets' component, and is moving the bug to that component. Please correct in case you think the bot is wrong.

Comment 2

[anton.kosyakov]

It is an issue in VS Code implementation of WebSocket protocol. VS Code is not processing ping requests from Firefox. This issue didn’t arise with Chrome since Chromium doesn’t initiate client-side pings.