1461402 - Dragging maximized firefox from secondary causes firefox to go into fullscreen mode (like pressing F11)

Status: NEW

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

Description

[psidhu.devel]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:60.0) Gecko/20100101 Firefox/60.0
Build ID: 20180509235650

Steps to reproduce:

System: Ubuntu 16.04 + Cinnamon 3.6.7 + Firefox 60 + two monitors

Set browser.tabs.drawInTitlebar to true

Place firefox onto secondary screen and maximize it. Attempt to drag it by either holding ALT + mouse drag or mouse drag from top bar.




Actual results:

Firefox goes into Fullscreen mode (same effect when you hit F11). I can hit F11 and it changes to unmaximized size.




Expected results:

Should have changed size to unmaximized window size and allow itself to be dragged. 

This issue does not happen if browser.tabs.drawInTitlebar is set to false.

This issue also goes away if I add a "panel" to my secondary. By panel, I mean the bottom panel that can hold the "Menu" button, date etc.

Comment 1

[Daniel Bodea [:danibodea]]

Hi psidhu.devel,

I have attempted reproducing this issue, but I was constantly unsuccessful.

This is what I did:
Sistem:
- Intel laptop with an extra monitor
- Ubuntu 16.04 LTS.
- Cinammon Theme installed
- Firefox 60.0.2

STR:
1. Went to "about:config" page and set the "browser.tabs.drawInTitlebar" preference from the default "false" to "true".
2. Opened Firefox and maximized it on the secondary monitor.
3. Dragged it around both monitors both with a mouse or track-pad, both using "Alt" key" or just dragging the top bar.
Could not reproduce the issue at all.
Note: No bar is displayed

Please reconfirm the reproduction of this issue.
Do you think you can provide any more details than those you wrote in the description? Can you correct my steps?

Comment 2

[psidhu.devel]

Hi, thank you for testing.

I am still seeing the issue. The only difference in our setup that I'm seeing is that I'm using a laptop with two external monitors, with the laptop monitor off. Both monitors are at a resolution of 1920x1200 (16:10).

Please see this screen capture video I took showing the issue: https://drive.google.com/open?id=19F_cTw3uLVYjBfupbfxoYO1TWTF83ug_

I've also found another user on the web that has encountered this: https://askubuntu.com/questions/1012519/firefox-goes-full-screen-when-dragged-from-secondary-to-primary-monitor

Comment 3

[psidhu.devel]

I'd like to add that there's apparently a cinnamon workaround for this that I just found:
* https://github.com/linuxmint/Cinnamon/issues/7598
* https://github.com/linuxmint/muffin/commit/edf0ce49e39b3dd85a3ee1110c83f8b9c46adfe8

I haven't tested it out, however.

Does this invalidate the bug as a bug in Cinnamon or is there still a Firefox bug?

Comment 4

[Daniel Bodea [:danibodea]]

I could validate this issue on a desktop computer with 2 monitors and Ubuntu 16.04 xenial (i686), on all the tested firefox versions: Release v60.0.2, Rease ESR v60.0.2, Beta v61.0b12, Nightly v62.0a1.

Comment 5

[Xidorn Quan [:xidorn] UTC+10]

I have no idea off hand why this can happen, but it's clearly a frontend issue rather than layout.

Comment 6

[Xidorn Quan [:xidorn] UTC+10]

Looking at the fix mentioned in comment 3, I suspect it could be an issue in Cinnamon which asks Firefox to enter fullscreen. It isn't clear to me, though, why would that happen.

Comment 7

[Xidorn Quan [:xidorn] UTC+10]

So if it is the system which tries to make the window fullscreen for some reason, this bug probably better be in Widget...

Comment 8

[Firefox Bug Husbandry Bot]

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