1472440 - Triggering fullscreen when moving window

Status: NEW

(Core :: Widget: Gtk, defect, P5)

Description

[Ralph]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:62.0) Gecko/20100101 Firefox/62.0
Build ID: 20180628175621

Steps to reproduce:

I disabled the 'Title Bar' under customization. ('Drag Space' don't seem effect this bug). (Have a multi screen set-up.) When dragging a window from one screen to the other screen it triggers 'Full screen mode'. But can also be reproduces on one screen.
Details: I maximize the window and drag from the top bar down. This will trigger 'Full screen mode'.
This problem seems to be something to do with the 'primary display', I can only reproduce this on non-primary displays. (did some small tests and seem consistent)


Actual results:

It unintentionally trigger Full screen mode. 
Fix after this happens: I can usually use F11 to exit full screen mode, but sometimes (20%) this will not trigger the exit, but will stay in full screen mode. (Only way to fix this is closing window or restarting Firefox.) {might be 2 separate bugs}


Expected results:

It should unmaximize the window and allow me to move it around. (stick to cursors)

Comment 1

[Ralph]

This same bug also happens when moving the windows using the 'alt'-key set by the system.
(This only happens when the window is maximized and then moved. This is true for the whole bug)

Comment 2

[David Olah]

Hi Ralph,

I tried On Firefox 61, 62 and Nightly 63 on Ubuntu 16.04 and didn't managed to reproduce the issue on neither of them after disabling the Title bar. When I maximize the window, on either the main or the secondary screen, I am able to move the window and it doesn't become Full screen.

Can you please try to reproduce it also on Nightly? You can download it from here: https://download.mozilla.org/?product=firefox-nightly-latest-ssl&os=linux64&lang=en-US ?

If it is still reproducing, can you describe the steps more precisely or upload a video recording of the screen of how you reproduce the issue?

Comment 3

[Ralph]

Hello David,

I just installed Firefox Nightly (63.0a1 2018-07-04 64bit) on my Linux Mint Cinnamon and got the same bug.
I also tested this on my laptop (similar but not the same setup. 62.0b5 64bit, aurora channel), attached a screen and got the exact same result.

I recorded a small clip on my secondary screen. https://www.youtube.com/watch?v=uCl3-Ke3o9E
This is just a new window, if I move it to the top of my screen you can see it maximize (expected) (0:06)
At 0:10 I drag the title bar down it should unmaximize the window but instead goes to fullscreen mode.
At 0:12 I drag it down again to unmaximize it but it stays in fullscreen (don't know what it should do, but not totally unexpected)
At 0:14 I hit F11 on my keyboard to toggle fullscreen mode and it goes back to the window mode.
I later move the window and do it again.
Move the window to the side of the screen. And drag it, and behaved as expected.

It is weird to have the window behave different on my primary screen (where everything behaves as expected).
So I added a panel to the screen, little bar the the bottom of my screen, and this seem to fix the problem.
See: https://www.youtube.com/watch?v=XFHMQCOkHMs
Note the small grey bar the the bottom of the screen, this is the pannel.

So Firefox only seem to have this behavior when it can goes to the maximum screen size. (I can see how this is a programming bug with fullscreen in Firefox).

----

Then somewhat unrelated but separate bug I think.
Sometimes F11 is not able the release the window from fullscreen mode.

In this video: https://www.youtube.com/watch?v=iy8T33Wq0hk I try to reproduce the bug, just dragging down the top and pressing F11.
At 0:19 I trigger some weird bug (not what I want but a bug non the less).
[screen is not responding to F11 or some clicks. But I don't click on everything. Might be a bug for some other time.]
At 0:53 I trigger the bug I want to describe here.
Every time you see the top come down it is because I press F11. (or hover over it with my mouse)
Between 0:59 and 1:08 I press the F11 key once and then a few more times.
The menu comes down and goes back up (not leaving fullscreen mode).
I later fix this by unmaximizing and triggering the bug above and then properly unmaximize the window.

----

I hope these show the problem and how to reproduce it.
I think it has to do with the windows taking up the full 1920x1080 screen and 'thinking' it is in fullscreen mode but it is in window mode. This is probably in a if-test somewhere that checks fullscreen mode by the resolution and not the proper variable(s).

(all videos are recorded with Firefox 62.0b5 (64-bit), aurora channel, but nightly behaves the same)

Any questions or to check for a fix, just ask.

Comment 4

[Andrew McCreight [:mccr8]]

Xidorn, could you maybe take a look at this? Thanks.

Comment 5

[Xidorn Quan [:xidorn] UTC+10]

I would first suspect it is the window manager you are using is doing something weird like treating maximization as fullscreen. I think I've seen similar bug report from Linux users before and it turned out to be that way.

In case you cannot fix your window manager, you can probably just disable the toolbar auto-hiding and use it like maximized I guess...

Comment 6

[Firefox Bug Husbandry Bot]

https://bugzilla.mozilla.org/show_bug.cgi?id=1552613

Comment 7

[BugBot [:suhaib / :marco/ :calixte]]

The bug has a release status flag that shows some version of Firefox is affected, thus it will be considered confirmed.