1638914 - "watchedByDevTools can only be set on top BrowsingContext" exception when opening the MBT with fission enabled

Status: RESOLVED FIXED

(DevTools :: Framework, defect)

Description

[Alexandre Poirot [:ochameau]]

This comes from this line:
https://searchfox.org/mozilla-central/rev/9193635dca8cfdcb68f114306194ffc860456044/devtools/server/actors/targets/browsing-context.js#1618
When we spawn targets for remoted iframes in a tab.
In order to reproduce, you would need a page with an iframe using an origin different from the top level tab document.

In this particular case, the watchedByDevTools attribute is already toggled by the top level target, so there is no need to toggle it again in additional targets.
This attribute may later be set by the TabDescriptor or Watcher actor only once, on the top level target BrowsingContext.
See:
https://phabricator.services.mozilla.com/D65983

Comment 1

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

Set release status flags based on info from the regressing bug 1620966

Comment 2

[Chris Peterson [:cpeterson]]

Tracking DevTools Fission bugs for Fission Nightly milestone (M6c).

Comment 3

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

The severity field is not set for this bug.
:ochameau, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 4

[Alexandre Poirot [:ochameau]]

Attachment: Bug 1638914 - Fix watchedByDevTools exceptions when debugging with Fission ON.

This attribute can only be toggled on top level BrowsingContext.
These are the top level window's, or tab's BrowsingContext.
From DevTools point of view, it should only be toggled by the
Parent Process or Tab target.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e3c129f197ec
Fix watchedByDevTools exceptions when debugging with Fission ON. r=jdescottes

Comment 6

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/e3c129f197ec