Incorrect font size use sticks after virtualbox window is moved to the second display

[ci-zephyurus]

Host Windows 10 PRO
VirtualBox 7.0.2
Guest: Debian GNU/Linux
uname -a
Linux ip030 6.0.0-2-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.0.5-1 (2022-10-28) x86_64 GNU/Linux

I have two monitors attached to the PC.

I have experienced a very annoying font size problem.

When the VirtualBox window is moved to the second display, virtualbox suddenly causes the guest linux to use very large font.

The problem is that even after I move the virtual box window back to the original 1st display, the large font size is still used and it is really unusable after this happens. I think the change of font size on the 2nd display may be related to the different display resolution and used font size (there is an multiplication factor I set using individual config of the display, etc. I am using the Japanese Window and so I don't know the menu names for these settings in English.)

The only reference related such a font size issue I can find is the comment in comment 3 of ticket Ticket #20282.

but it uses a wrong font size if it is on the 2nd screen. 

Please note that strange font size usage when the program window is moved from the 1st window to the 2nd window is observed for many applications. MS EXCEL, MS WORD, Thunderbird mail client to name a few, especially only half the window is shifted to the 2nd window. However, many programs resume to use the right font size once the program window is reverted to the 1st window, or completely moved to the 2nd window.

VirtualBox is the only program that keeps on using strangely large font size even if I move the window back to the original. And for that matter, it keeps on using the strangely large font and it becomes unusable for my purpose. Once VBox is retarted, the problem goes away, but it is very undesirable.

I will attach screen captures to explain the problem, but I am not sure if I can get the screen dump when the VBox window is split between the two windows. I will take a photo in that case.

[boxer01]

Is this issue still present in the current version?

[ci-zephyurus]

Thank you for the question. I am sorry that I obviously forgot to upload the different font sizes used in different windows.

Right now, I can say that if I move the virtualbox window to the screen where it is usually used, the font size reverts back to the original size and so it is not as bad as it was when I filed this entry.

But for the sake of completeness, I am going to post the virtualbox window when it is moved to the second monitor to show how the font size changes mysteriously.

[ci-zephyurus]

Original screen. Note the smallish font size. I only captureed the upper half of the window to avoid the size limit of upload.

[ci-zephyurus]

When I move the virtualbox window to the 2nd screen, suddenly I get a largish font size (which may be reasonable because the resolution of the 2nd monitor is about half the 1st screen).

[ci-zephyurus]

It used to be that the virtualbox window used the big font even when I moved it back to the first screen. But now it properly reverts to the original font size. Sometimes I have to close the window and make it full screen window to get the proper font size, but it now works.

The first display is DELL S2817Q and has 3480 x 2160 resolution. (I am using 200% font enlargement on the host windows).

The second display is HP Z24n G2 and has 1920 x 1200 resolution. (Font size is at 100% enlargement. That is, no change.)

[ci-zephyurus]

It is hard to figure this out, but if the font used in the second window is used back in the １st window, it was twice as big as the original font (maybe because of the 200% enlarge factor or something). I wish I had captured the original screens. I am now using 7.0.18 and the guest addition that goes with it, and the problem is no longer noticed.

[boxer01]

I added your ticket to the list of the graphic issues in my graphics ticket #21515, months ago. Just so you know. ;-)

So, should this ticked be closed or not?

[ci-zephyurus]

Replying to boxer01:

I added your ticket to the list of the graphic issues in my graphics ticket #21515, months ago. Just so you know. ;-)

Thank you for looking after these bug reports including mine.

So, should this ticked be closed or not?

Yes, as far as the issue of "font size is not reverted" when VBox window is moved to a display screen and moved back, this bug can be closed.

Too bad, I could not tell exactly when this was fixed. This is because I was so afraid of moving VBox window to a different display because restoring the font size properly after bringing the window to the original was hit and miss issue and the only way to reliably restore the font size was restarting VBox. :-(

So I did not know this was more or less fixed until three weeks ago when I was asked about it.

Thank you again.