Bug 493495

Summary: Cursor disappears at the bottom of the screen while using Flatpaks
Product: [Plasma] kwin Reporter: Fernando M. Muniz <fernandommuniz>
Component: generalAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED DOWNSTREAM    
Severity: normal CC: cwo.kde, kde, nate
Priority: NOR    
Version First Reported In: 6.1.5   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Notice the cursor over the bottom of the panel going to LibreWolf
Issue still happens when windows are not maximized.
Monitor settings.
cursor

Description Fernando M. Muniz 2024-09-22 17:25:32 UTC
Created attachment 173970 [details]
Notice the cursor over the bottom of the panel going to LibreWolf

The cursor disappears when it's the bottom of the screen while using flatpak apps like Firefox and LibreWolf.
In everything else, you can see a bit of the cursor, which is consistent with the other corners of the screen.
Comment 1 Nate Graham 2024-09-23 17:07:38 UTC
Does this reproduce when the apps aren't maximized? How about in other Flatpak apps, or is it only seen in those two? This is on Wayland, right? Or X11?
Comment 2 Fernando M. Muniz 2024-09-23 17:27:12 UTC
Created attachment 173991 [details]
Issue still happens when windows are not maximized.

I'm using wayland.
org.qbittorrent.qBittorrent, com.obsproject.Studio, org.gimp.GIMP, org.kde.kdenlive are not having this issue.
org.gnome.Calculator, org.blender.Blender, org.torproject.torbrowser-launcher has this issue.

When testing in non-maximized windows I've not only noticed that the issue still persists, but I've also noticed that these flatpaks with these issues for some reason switches the cursor image/theme.
Comment 3 Vlad Zahorodnii 2024-09-23 17:36:29 UTC
Do you use fractional scaling? How many outputs do you have?
Comment 4 Fernando M. Muniz 2024-09-23 17:39:38 UTC
Created attachment 173992 [details]
Monitor settings.

(In reply to Vlad Zahorodnii from comment #3)
> Do you use fractional scaling? How many outputs do you have?

I only have one monitor. The scaling is at 100%
Comment 5 cwo 2024-09-23 18:08:44 UTC
If you look closely, that's not Breeze cursors in the Librewolf window; the tail is long and thin rather than short and stubby. On the panel/desktop, it's Breeze.

I suspect that Librewolf is using the Adwaita cursors as fallback because Breeze is not available in the sandbox. If you switch to Adwaita cursors on the main system, do you get the same effect outside of Flatpak windows?
Comment 6 Vlad Zahorodnii 2024-09-23 18:22:08 UTC
Created attachment 173996 [details]
cursor

It looks like a client bug. From what I see, blender sets a hotspot such as (3, 0), but the cursor pixmap has blank contents at that point (see the attachment). Judging by the pixmap, the hotspot needs to be something like (5, 4) or something.

Speaking for kwin, it keeps the cursor hotspot 1 pixel away from the bottom screen edge, which is still not enough because the cursor start at (4, 2)
Comment 7 Vlad Zahorodnii 2024-09-23 18:23:33 UTC
Please report this issue to the developers of the affected applications.