Breeze style problem since Qt 6.8.2

[Jean-Baptiste Mardelle]

On Saturday, March 8, 2025 7:06:18 PM Central European Standard Time Tobias 
Leupold wrote:
> Hi all!
> 
> There's a style problem with Breeze that emerged with Qt 6.8.2: QSpinBoxes
> take too much vertical space if an application-wide style sheet is set. Even
> setting a single space as the style sheet already triggers this, it has
> nothing to do with a spinbox-specific style.

Hi!

For what it's worth, I am also seeing this problem in Kdenlive. Didn't have 
time to investigate, but I can confirm that setting any non empty style sheet 
on a widget that contains a QSpinBox makes it use 1.5 - 2 times the vertical 
space with Qt 6.8.2 anf KF 6.11 using Breeze style.

Regards,
Jean-Baptiste

> This does not show up with Fusion. And also not in Breeze, as long as no
> application-wide style sheet is set. I suppose most KDE apps don't use
> application-wide styles, so not many devs may have already noticed this.
> However e.g. KPhotoAlbum is affected.
> 
> I first thought this was a Breeze bug. Along with some hints from the Qt
> forum, I opened a respective bug report:
> 
>     https://bugs.kde.org/show_bug.cgi?id=499906
> 
> However David Redondo said this should be an upstream Qt bug. So I filed one
> there:
> 
>     https://bugreports.qt.io/browse/QTBUG-133845
> 
> ... where Christian Ehrlicher said he thinks it's a Breeze issue.
> 
> So ... now the cat is biting its own tail. I have never worked on style
> stuff before, so I don't know anything about this. Is anybody with more
> insight of this willing to have a look at that issue? So that we can either
> get this fixed in Breeze or in Qt or maybe in both?
> 
> Thanks in advance for all help on tracking this annoying issue down!
> 
> Cheers, Tobias