GtkSpinButton's '+' changes width if insensitive

[Egmont Koblinger]

GtkSpinButton consists of a (typically numeric) input field, followed by a '-' and finally a '+' sign. The width of the '+' sign depends on whether it's sensitive or not. It shouldn't, it should have a constant width.

Happens with Ubuntu's default Ambiance and Radiance themes. Does not happen with GTK+'s default Adwaita.

Example 1: Open dconf-editor and navigate to /ca/desrt/dconf-editor/demo/integer-16-unsigned. Uncheck "Use default value" and use the +/- buttons to alter the value. As it reaches 65535, that is, the '+' button becomes insensitive, its width increases. Click '-' to make the '+' sign sensitive again, its width shrinks back.

Example 2: Open gnome-terminal, Edit -> Profile Preferences, Scrolling tab, toggle the checkbox in front of "Limit scrollback to" back and forth. Notice how the '+' sign keeps changing width, and the "lines" label keeps jumping back and forth accordingly.

ProblemType: Bug
DistroRelease: Ubuntu 17.10
Package: light-themes 16.10+17.10.20171115-0ubuntu1
ProcVersionSignature: Ubuntu 4.13.0-21.24-generic 4.13.13
Uname: Linux 4.13.0-21-generic x86_64
ApportVersion: 2.20.7-0ubuntu3.6
Architecture: amd64
CurrentDesktop: Unity:Unity7:ubuntu
Date: Sun Dec 31 22:08:32 2017
InstallationDate: Installed on 2016-11-09 (416 days ago)
InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2)
PackageArchitecture: all
SourcePackage: ubuntu-themes
UpgradeStatus: Upgraded to artful on 2017-09-21 (100 days ago)

[Daniel van Vugt (vanvugt)]

Thank you for reporting this bug to Ubuntu.
Ubuntu 17.10 (artful) reached end-of-life on July 19, 2018.

See this document for currently supported Ubuntu releases:
https://wiki.ubuntu.com/Releases

We appreciate that this bug may be old and you might not be interested in discussing it any more. But if you are then please upgrade to the latest Ubuntu version and re-test. If you then find the bug is still present in the newer Ubuntu version, please add a comment here telling us which new version it is in and change the bug status to Confirmed.

[Egmont Koblinger (egmont-gmail)]

Can't reproduce on disco.