1554076 - Greyed out "Restore Previous Session" button is missing after a restart

Status: VERIFIED FIXED

(Firefox :: Session Restore, defect, P3)

Description

[Fanolian]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:69.0) Gecko/20100101 Firefox/69.0
Build ID: 20190523215203

Steps to reproduce

1. Open Nightly with a new profile.
2. Open hamburger menu. Make sure a greyed out Restore Previous Session button is present.
3. Make sure the option Restore previous session in about:preferences is disabled.
4. Restart Nightly, either by Ctrl-Alt-R in Browser Console or from a clicking a Nightly update.
   Note: do not close Nightly and reopen it.
5. Open hamburger menu again.

Actual result

Restore Previous Session button is missing from the hamburger menu.

Expected result

Like previous builds, a greyed out Restore Previous Session button is present even if no sessions can be restored (either session is missing or already restored).
The button, active or greyed out, should always be present in the hamburger menu if Restore previous session is disabled in about:preferences.

Additional Notes

If I pin all tabs, close Nightly and reopen it, the greyed out Restore Previous Session button is still present.

Comment 1

[Dão Gottwald [:dao]]

Apparently there's a problem with isAutomaticRestoreEnabled():
https://searchfox.org/mozilla-central/rev/662de518b1686c4769320d6b8825ce4864c4eda0/browser/base/content/browser.js#8061

Comment 2

[Mike de Boer [:mikedeboer]]

Aaah, so it's about the button being there (visible) or not, reflecting the current pref configuration. So the only thing that may have changed here is that value of browser.sessionstore.resume_session_once is now properly captured, since we're caching its initial value at early startup.
This pref is always set back to false, so it would've changed the return value of isAutomaticRestoreEnabled() between early and late startup.

I think we need to tweak the button hiding mechanism a little to not take resume_session_once into account.

Comment 3

[Mike de Boer [:mikedeboer]]

Attachment: Bug 1554076 - Stop relying on the startup module - SessionStartup.jsm - to inform us of the runtime state, which is the responsibility of SessionStore.jsm. r?dao!

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/21e712ba55fb
Stop relying on the startup module - SessionStartup.jsm - to inform us of the runtime state, which is the responsibility of SessionStore.jsm. r=dao

Comment 5

[Oana Pop-Rus]

https://hg.mozilla.org/mozilla-central/rev/21e712ba55fb

Comment 6

[Fanolian]

Fixed in 20190528214841. Thanks.