[KDE] Lists cutting off the bottom of characters after upgrade from 19.04 to 19.10

[stevenE]

Hi,

I've just upgraded from Kubunut 19.04 to 19.10, but some KDE applications are cutting off the bottom 25% of characters in some areas of their screens, but not in others. See the screenshot below from the System Settings - Font Management screen.


I've also seen the same problem with Kmail, it shows the folder listings and message pane fine, but the message list has this issue. I thought this might be related to the fact I'm using a HiDPI screen, and have the "Force Font DPI" ticked and set to 196, but de-selecting this and restarting the application shows the fonts still truncated (but much smaller as expected). Changing font size also has no change to the truncation, fonts are still cut off about the same point in the characters.

Anyone have any ideas what to do to investigate further?

Thanks

[Snowhog]

What Themes are you using?

[stevenE]

What Themes are you using?

I'm using the Kubuntu theme, but also tried with Oxygen and Breeze Dark with no change in this behaviour.

[claydoh]

What video card?

My suggestion is to try going a little lower on the DPI and see if that fixes, and/or try scaling the desktop and/or adjusting the font size. HiDPI is still awkward it seems, though it is much better these days.

I am not seeing this on my 19.10 system with an AMD RX560 with the dpi at 192, but the monitor scale adjusted to 1.6 and the stock font sizes, and connected to my 4k 40" TV.
I can't make it replicate the issue, so I wonder if the video card is contributing to things.

[stevenE]

Hi, thanks for the reply.

I've done a bit more playing about. I created a new user, logged in as that, saw that the fault doesn't exist (at least in the font manager screen). Forced the DPI to 196 and the problem appeared. Removed it and the problem disappeared. Playing around with DPI and it appears that this is where the problem is, the higher the DPI setting the larger the amount on the character truncation. Not sure how to explain how you can't re-create it however, makes me wonder whether there is something in my system configuration, probably there since I first got a HiDPI laptop, that is causing this, but no idea what I did back then.

Logged back in as my normal user, removed force DPI and the problem disappeared in the font management screen, but still remained with Kmail.

Changing font sizes has no effect on the bottom of characters being truncated, the same bits of each character are lost whatever the font size.

I've not got screen scaling enabled.

Video card is a Radeon HD 2350.

[Snowhog]

Try clearing all caches and restarting/rebooting.

[stevenE]

So I've disabled forced font DPI, cleared /var/tmp/kdecache-USER and rebooted, but still the same truncation of characters in Kmail. Are there some other caches I'm missing?