User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:95.0) Gecko/20100101 Firefox/95.0

Steps to reproduce:

Since installing FF 95, I sometimes cannot go back to the first history item of a tab. This happens most frequently with google.com, but also with other sites like nytimes.com.

Actual results:

Hit the Back button or action, or choose the first history item from the back menu. The page in the tab does not go back to this item, but gets stuck at the second item in the history.

Expected results:

I should go back to the previous / first history item, or the one that I choose.

The Bugbug bot thinks this bug should belong to the 'Core::DOM: Navigation' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Christiaan, would be great if you had steps to reproduce.
Like, do you perhaps click back while the current page is still loading or something like that?

Do you have any addons installed?

No, I hit Back when the page is fully loaded. Also choosing the first history item does not work, even though it is there. There is nothing different from other navigation actions when this happens. It just sometimes happens. And sometimes not. So I cannot give steps to reproduce, as I cannot consistently reproduce it. But this never happened before FF 95, this is a new bug introduced in that version.

You probably got Fission enabled when updating to 95, and Fission means that session history lives in the parent process, when it without Fission lives in the child process.

Can you think of any particular pages where this happens more often. Like, is it from google.com -> search results -> some particular website -> try to go back?

smaug says he has reproduced this bug once on YouTube with bfcache.

I and peterv do track this through ship-regressions.

I have tested this on the latest versions of Firefox Nightly 98.0a1 (2022-02-02), beta 97.0 and release 96.0.3 and also 95.0 (release version) (on MacOS 10.15.7) but I couldn't reproduce the issue the way it occurs for the reporter (in any of the three scenarios : clicking back, using keyboard shortcuts or going directly to the first page from the history through the context menu).
Tested with fresh and dirty profiles (but without addons).

If anyone has some specific scenarios on how it occurred please share afterwards and I will test it that way as well. I will try to test it some more and see if anything comes up. Will update if the result changes.
Need/info me for any information/testing I could help with.

Christiaan, have you seen this recently? Especially with if you use Nightly 99. It has gotten some other session history related fixes recently.
(My guess is that this has something to do with requestedIndex)

(In reply to Olli Pettay [:smaug] from comment #8)

Christiaan, have you seen this recently? Especially with if you use Nightly 99. It has gotten some other session history related fixes recently.
(My guess is that this has something to do with requestedIndex)

I am still seeing this occasionally in the latest release (97.0). I don't use the nightlies, so I cannot comment on 98.x and 99.x.

I retried this on the latest versions of Nightly, beta and release but can't reproduce it still.
Christiaan do you have maybe some more specific steps for us to try ?

(In reply to Andrei Purice from comment #10)

I retried this on the latest versions of Nightly, beta and release but can't reproduce it still.
Christiaan do you have maybe some more specific steps for us to try ?

I now see it only very rarely, and I don't have steps to consistently reproduce it.