500150 - unexpected behaviour with private browsing and full screen mode

Status: RESOLVED WORKSFORME

(Firefox :: Session Restore, defect)

Description

[Matthew Shepherd]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.1) Gecko/20090616 Firefox/3.5 (.NET CLR 3.5.30729)
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-GB; rv:1.9.1) Gecko/20090616 Firefox/3.5 (.NET CLR 3.5.30729)

Browser behaves unexpectedly when I start private browsing with shift-control-p, go full screen with F11 and then stop private browsing with shoft-control-p. the browser loses full screen mode (I guess it remembers it's state from when it was last in normal - non-private browsing mode)  but it loses the windows borders. See http://screencast.com/t/hxnWkK8Ut8L which illustrates what happens.

Reproducible: Always

Steps to Reproduce:
1. Start private browsing with Shift+Control+P
2. Go fullscreen with F11
3. Stop private browsing with Shift+Control+P
Actual Results:  
Window goes back to the size it had when private browsing was started, but with no windows borders or title bar. It looks like it's in full screen mode, but not taking up the full screen if that makes sense.

Again, this illustrates the bug nicely: http://screencast.com/t/hxnWkK8Ut8L

Expected Results:  
At point 3 above, I'd expect it to either:

maintain full screen mode but go back to the tab state when private browsing was started

OR

go back to normal screen mode, but with the proper windows borders and title bar.

I've disabled all add-ons and selected the default theme before running this test.

Comment 1

[u88484]

I'm not sure if this bug should be part of toolbars, private browsing or some core component so I'll get QA to get a look at this.

Comment 2

[(no longer active)]

This looks like a bug in SessionStore's setBrowserState API.  Simon, is there already a SessionStore bug filed about this?  Also, I tried to reproduce this on Linux, but on that platform the state of the window is not changed on private browsing mode transitions, on every combination that I could think of.

Comment 3

[Simon Bünzli]

(In reply to comment #2)
> is there already a SessionStore bug filed about this?

No, please either file one or move this one: we should either also save/restore full screen mode - or at least not try to resize the window when we're already in it (AFAICT this bug doesn't happen when the window was maximized before going into full screen mode).

Comment 4

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Same happens on OS X. Ehsan, shall we file a new bug or move this one? Would be nice to see some progress.

Comment 5

[aravindm]

Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.5; en-US; rv:1.9.3a5pre) Gecko/20100513 Minefield/3.7a5pre

Scenario 1:
Able to reproduce the bug with the given steps in Description when :
Firefox Window is resized (i.e., click on restore down, if it is in maximized mode)

Scenario 2: 
When firefox is in maximized state, unable to reproduce the bug.

General Question : Exiting Private Browsing mode does not exit the full screen mode. Is this expected ?

Comment 6

[(no longer active)]

As I said in comment 2, this is actually a sessionstore bug.  Moving the bug there...

Comment 7

[(no longer active)]

(In reply to comment #5)
> General Question : Exiting Private Browsing mode does not exit the full screen
> mode. Is this expected ?

Is there any good reason to change that behavior?

Comment 8

[Henrik Skupin [:whimboo][⌚️UTC+1]]

(In reply to comment #7)
> Is there any good reason to change that behavior?

I don't think so. We really should retain the current state of the windows when a transition in or out of the private browsing mode happens.

Comment 9

[Wayne Mery (:wsmwk)]

If this bug is truly major, shouldn't the blocking bugs be also?

Comment 10

[Adrian Florinescu [:aflorinescu]]

Using Firefox 94.0a1 (2021-10-03) on Windows 10, Ubuntu 20.04 and Mac 11 I couldn't reproduce this issue as described above(there is no shortcut to "stop" private mode). Marking WFM, please reopen if I missed anything.