1420917 - webRequest.onErrorOccurred unexpectedly fires with NS_ERROR_NET_ON_RECEIVING_FROM when a listener is added in onHeadersReceived while the devtools is open

Status: NEW

(WebExtensions :: Request Handling, defect, P5)

Description

[Rob Wu [:robwu]]

Attachment: webrequestErrorOccurredOnReceiving.zip

STR:

1. Download the attached extension.
2. The zip file contains repro.py and server.pem. Extract these to the same directory and start repro.py
3. Visit https://localhost:4433/ and confirm the security exception.
4. Open the devtools for the tab (this is needed to reproduce the bug, you don't need to interact with it).
5. Reload the page.
6. Look at the global JS console or the extension's background page's console.

Expected:
onHeadersReceived

Actual:
onHeadersReceived
onErrorOccurred NS_ERROR_NET_ON_RECEIVING


This only happens when I add the first onErrorOccurred event listener from the onHeadersReceived event and then keep the request suspended.
If I register a listener for onErrorOccurred before initating a request (uncomment the code in the attached background.js), then the bug does not occur.