1304255 - All GUI popups are displayed in wrong place (but only sometimes)

Status: UNCONFIRMED

(Core :: XUL, defect, P3)

Description

[Skylar Ittner]

Attachment: What I get in step 3

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:48.0) Gecko/20100101 Firefox/48.0
Build ID: 20160811171047

Steps to reproduce:

I have two external monitors connected to my Linux Mint 17.3 (Cinnamon DE) laptop.

Steps:
1. Have Firefox open (maximized or not) on any monitor.
2. Do something to open a GUI thing.  I've done this with the Awesome Bar suggestions, the main "hamburger" menu, and popup autofill suggestions.  It does not work with the search box suggestions.
3. If it showed in the right place, it won't the next time you do it.  Try a few times.
4. Now resize the window (min/maximize, drag to different desktop, etc) and repeat 2 and 3.


Actual results:

Stuff goes everywhere it shouldn't.  It seems to recognize the mouse is in the right place (list items are highlighted), but shows the stuff somewhere else.  If I move the mouse pointer around in the space where something should be, the list items are highlighted accordingly, even if they're a monitor away.

See attachments.


Expected results:

Stuff should have gone where it's supposed to.

Comment 1

[Skylar Ittner]

Attachment: What I should get

Comment 2

[Skylar Ittner]

Attachment: The same bug, with the awesome bar instead of an autofill popup

Comment 3

[Skylar Ittner]

Attachment: Different screen, same problem, safe mode

Comment 4

[Skylar Ittner]

Attachment: This time with the main Firefox menu

Comment 5

[Skylar Ittner]

I *think* Menus is the closest component.

Comment 6

[Skylar Ittner]

Still happens on 49.