[Bug]: Full screen will open on whichever display has the mouse point, not the last display used

[roadSurfer]

Version

7.2.0

Host OS Type

Windows

Host OS name + version

KDE Neon (Ubuntu 24.04 based)

Host Architecture

x86

Guest OS Type

Linux

Guest Architecture

x86

Guest OS name + version

Windows 11, version 23H2, build 22631.5768

Component

Other

What happened?

Expected Behaviour

When starting a VM Guest is starts on the last display used.

Actual Behaviour

When starting a VM Guest directly in full screen, it will start on whichever display currently contains the mouse pointer and not the last display used.
If the VM Guest is switched out of full screen (Host+F) and back into windowed mode, then it will switch to the last display used.
This was not the behaviour with 7.1.12-169651

Workarounds

Start the VM Guest full screen and then:

1. Keep the mouse pointer on the desired display until the VM Guest has started; or
2. Switch the VM Guest to windowed, move the mouse pointer to the desired display, switch back to full screen

How can we reproduce this?

1. Have a host with multiple displays
2. Start a VM Guest
3. Make it full screeen
4. Fully shut it down
5. Start the VM Guest again and move the mouse pointer to a different display
6. Observe that the VM Guest starts on the other display, not the original

Did you upload all of your necessary log files, screenshots, etc.?

• Yes, I've uploaded all pertinent files to this issue.

[Dsen-orcl]

Could you please upload VBox.log file?

[roadSurfer]

Sure! This is just me opening the VM, it going to the "wrong" screen because that's where my mouse pointer was, and then some Host+C/Host+F to get it fullscreen on the "correct" screen.

VBox-Copy.log

[roadSurfer]

Had a quick fiddle with VBox today and it's not just on start, it's every time.

1. Have a guest running on screen 1
2. Host-F to make it windowed
3. Move mouse pointer to screen 2
4. Host-F again to make it full screen

Expection: VBox goes full screen on screen 1

Actual: VBox goes full screen on screen 2

This can be reporduced at any time. I guess that makes testing easier? 🙂

[Dsen-orcl]

Right, I haven't touched this one so far (as other defects have more priorities); but as soon as I get corresponding environment (dual-monitor Windows 11 host) I'll have a look. Thank you for your assistance!

[philippun1]

I can confirm this still happening with Virtualbox 7.2.4 on a Windows host. The issue is even worse when using two virtual screens, both of the screens will be fullscreened on one monitor on top of each other. This makes fullscreen with multiple screens completely unusable.

[Dsen-orcl]

Hello guys, could you please test the development testbuild where I've tried to fix the issue, here is the link:
https://www.virtualbox.org/wiki/Testbuilds <= please look for "development revision 171043".
Thanks in advance!

[philippun1]

@Dsen-orcl I can confirm that the virtual screens are fullscreened on the display they are currently on with the 171043 version.