This is pretty tricky to fix, mostly since I can't rely on the image-button styleclass. Image buttons with a icon up to 24x24px inside are squared though.

why can't you rely on it ?!

As someone who doesn't quite recall all of the contexts of image-buttons and reasoning behind using min-width for image buttons, I am attaching the following patch that "makes things look reasonable to me". Lapo will likely be able to tell me why this is foolish to do. I've been wrong before...

Created attachment 322975 [details] [review]
Adwaita: add padding to image buttons

- This brings the image button metrics closer to what was in 3.18

Matthias I can't rely on image-button/text-button classes since those are wrongly places a lot of times.

Jakub, something like could work, If I'm not missing something, but you should check your math, 28+4+4 != 32 :-)

fixed with commit 08613dce92d1b0badd118c837da5013f6995e69a

Hey, maths is hard.