Thanks to :rfeeley for noticing this and helping work through it on slack. Steps to reproduce:
- Trigger the about:newinstall page to indicate migration to a separate profile for nightly. (I don't know the "right" way to do this, but browsing directly to
about:newinstall?endpoint=https%3A//accounts.firefox.com/ seemed to do the job)
- Enter your email in the form to connect to sync, which will open the FxA login page in a new window
- Complete the FxA login flow
- Click the hamburger menu in the browser and observe whether the user is signed in
Expected result: I'm signed in to sync in the browser.
Actual result: The hamburger menu still shows "sign in to sync", indicating that I was not successfully signed in to the browser.
What I believe is happening, is that the new tab opened in step (2) is missing the
context query parameter. It should include
context=fx_desktop_v3 so that the page knows how to communicate login state back to the browser.
The patch from Bug 1518632 declares a
$CONTEXT variable with the correct value here:
But its value doesn't seem to be used when constructing the URL for FxA here:
Manually adding it to the URL of the tab opened at step (2) fixes the issue for me.