1191507 - Black area in fullscreen mode on a multi-display system

Status: RESOLVED DUPLICATE of bug 910144

(Core :: Widget: Cocoa, defect)

Description

[Roman Verchikov]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:39.0) Gecko/20100101 Firefox/39.0
Build ID: 20150630154324

Steps to reproduce:

1. Get multi-display system (I'm able to reproduce this on MBP with 2 external monitors attached, cannot reproduce this on system with one physical screen)
2. Move Firefox to fullscreen mode
3. Switch (Cmd+Tab, mouse, or anything else) to another application running on the same physical screen.
4. Switch back to Firefox


Actual results:

Black area above Firefox window appears. The size of black area is *precisely* the same as OSX system menu bar.


Expected results:

Firefox should stay fullscreen without any black areas at the top

Comment 1

[[:Towkir] Ahmed]

Feel free to move back If I am wrong about the component :)

Comment 2

[Roman Verchikov]

Attachment: bug-1191507-black_area_above.png

Just to be clear on what I meant with "black area above Firefox window".

Comment 3

[Timothy Nikkel (:tnikkel)]

This sounds familiar, is there an existing bug on this?

Comment 4

[Xidorn Quan [:xidorn] UTC+10]

I believe this is a widget issue.

Comment 5

[Xidorn Quan [:xidorn] UTC+10]

Yeah, it sounds familiar, but I don't find any existing bug on this.

BTW, I cannot reproduce this issue on OS X 10.10 with Firefox 39. Probably a 10.9 bug which we probably need to workaround? I'm not quite sure.

smichaud should probably be aware of if there is any similiar issue.

Comment 6

[Roman Verchikov]

I can only reproduce it with three physical screens, all works fine for two or one screen.

Comment 7

[Roman Verchikov]

I apologize for the message above, it's NOT correct. I can reproduce it on a system with two physical screens, as well as on system with three physical screens.

Comment 8

[Steven Michaud [:smichaud] (Retired)]

Here's better STR, testing with FF 40.0.2 (the current release) on a Retina MacBook Pro running OS X 10.9.5:

1) Attach a secondary monitor.
2) Start FF and move its browser window to the secondary monitor.
3) Start Safari and move its browser window to the secondary monitor.
4) Make FF go fullscreen (for example by clicking on the fullscreen button).
5) Cmd-Tab to switch focus to Safari (not in fullscreen mode).
6) Cmd-Tab to switch focus to FF (still in fullscreen mode).

I find this shows the bug 100% of the time.