Bug 486766

Summary:	Gtk-WARNING **: GtkGizmo 0x6127b629ff10 (slider) reported min height -2, but sizes must be >= 0
Product:	[Plasma] Breeze	Reporter:	Benjamin Hennion <benjamin.hennion>
Component:	gtk theme	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	agrinev98, benjamin.hennion, uhhadd
Priority:	NOR
Version First Reported In:	6.0.2
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	UI file with Scrollbar

Description Benjamin Hennion 2024-05-08 06:58:21 UTC

Created attachment 169293 [details]
UI file with Scrollbar

SUMMARY
Whenever a GtkScrollbar is displayed, the terminal outputs:

> Gtk-WARNING **: 08:38:04.284: GtkGizmo 0x6127b629ff10 (slider) reported min height -2, but sizes must be >= 0

This does not happen with GTK_THEME=adwaita, so it is most likely a breeze-gtk issue.
See also https://gitlab.gnome.org/GNOME/gtk/-/issues/4446 which suggests such issues are CSS-related.

STEPS TO REPRODUCE
1. Download the attached gizmo.ui. It contains a GtkWindow with a GtkScrollbar. 
2. Open it via `gtk4-builder-tool preview gizmo.ui` (with breeze as gtk theme in KCM)
3. See the warnings in the terminal output.
4. Try again with `GTK_THEME=adwaita gtk4-builder-tool preview gizmo.ui`. No warnings.

OBSERVED RESULT
> Gtk-WARNING **: 08:38:04.284: GtkGizmo 0x6127b629ff10 (slider) reported min height -2, but sizes must be >= 0

EXPECTED RESULT
No warning