I just quit Firefox to change a setting (disabling web-render, but I've seen this on random session restores a few times).

I had three tabs open:

1. Gmail
2. A blog post
3. about:config

When I restarted, the three tabs were what I expected, and about:config loaded again. Cool.

Then I switched back to tab 2, which had the blog post i was reading. The tab text had the right info on it, but when I switched to the tab firefox navigated to an old URL that I think was in that tab earlier.

Then, while writing this bug report I bothered to load the gmail tab: Same thing happened. Sudden navigation.

I say navigation because in both instances the expected tab shows up in the back button history as the previous page, and hitting back takes me back to the expected page.

This has happened intermittently on restart for nightly update for a while.

The priority flag is not set for this bug.
:mikedeboer, could you have a look please?

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Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is -- (Backlog,) indicating it has has not been previously triaged, the bug's Severity is being updated to -- (default, untriaged.)

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is -- (Backlog,) indicating it has has not been previously triaged, the bug's Severity is being updated to -- (default, untriaged.)

Because this bug's Severity has not been changed from the default since it was filed, and it's Priority is -- (Backlog,) indicating it has has not been previously triaged, the bug's Severity is being updated to -- (default, untriaged.)

The severity of these bugs was changed, mistakenly, from normal to S3.

Because these bugs have a priority of --, indicating that they have not been previously triaged, these bugs should be changed to Severity of --.

Similar situation is here:
https://bugzilla.mozilla.org/show_bug.cgi?id=1522184

The only difference is the way the tab was made not active (by browser restart in this bug - Bug 1624083, or by discard extension - in Bug 1522184).

I have attempted reproducing this issue by repeating the steps described in comment 0 on a Windows 10 machine and a Nightly v79.0a1 browser.
I had no success reproducing it in any different situations I could think of.

Has this issue occurred again in the meantime? Do you have any new suspicions of the real cause of this issue?

Which operating system and browser version were you using when it reproduced? Thanks!

I've not seen this recently, no.

Adding the QA Whiteboard [qa-regression-triage], but please remove it it if new info is available for QA to reproduce it.

(In reply to Bodea Daniel [:danibodea] from comment #7)

… no success reproducing it …

(In reply to Matthew Gaudet (he/him) [:mgaudet] from comment #0)

… random …

… intermittently …

Gut feeling: think about whether – prior to quit – any open tab had been at any time in a discarded state.

Consider the equivalence (and sychronisation) of the three values mentioned in bug 1498432 comment 5. Probably not directly related, but maybe food for thought.

After re-attempting to reproduce the issue in bug 1624083 and bug 1522184, as those were reported as very similar, but wasn't able to confirm any of them by using the steps in the bug descriptions in both their originally reported versions as affected and the latest versions of Nightly.
I have attempted to discard the tabs before the restart or quitting action, however, I wasn't able to observe the reproduction of any suspicious behavior.

Also considering that the reporter has not observed the issue, later on, pet comment 8, I will set the whiteboard "QA-not-reproducible".

In case this issue reoccurs and further information is provided, please NI me to re-attempt reinvestigation of a regressor.

The severity field for this bug is relatively low, S3. However, the bug has 10 votes.
:dao, could you consider increasing the bug severity?

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