Comment # 23 on bug 1045798 from Fabian Vogt

(In reply to Stefan Hundhammer from comment #20)
> The screenshots tarball contains other permutations of the same scenario:
> Running from the root shell with different widget themes, running as a
> regular user with different widget themes, running as a regular user, but
> with "kdesu" with different widget themes.
> 
> There must be some Qt5 or KDE lib or plug-in that makes it behave
> differently.
> 
> I also checked on my workstation with yesterday's Tumbleweed, and it works
> fine there (all buttons using Alt-H, no shortcuts reassigned), but I am
> using Xfce there, not KDE. But the Qt libs are also the most recent Qt 5.9
> versions.

It's a side effect of
/usr/lib64/qt5/plugins/platformthemes/KDEPlasmaPlatformTheme.so
linking against libKF5XmlGui, which adds automatic checking (+replacement) of
button
accelerators on startup.

It can be disabled by putting

> [Development]
> AutoCheckAccelerators=false

into ~/.config/kdeglobals.

I suppose it could be worked around by not using kdesu, which also preserves
the environment variables triggering loading of the kde platform theme.

I'm not sure why the accelerators keep changing though, AFAIK that did not
happen
before recently (Qt 5.9?) and needs some more investigation.