Menu accelarator now requires holding alt?

[Craig Hall]

Hi there,

I recently tried updating my copy of Okular, and found that the menu
accelerator behaviour changed. Originally I could press Alt, then
press F, to open the file menu; but in the latter version I have to
hold Alt and press F.

I couldn't find anything is Plasma's system settings related to this,
so after some helpful tips from tosky in #okular I bisected the change
in Okular's behaviour to the following Nixpkgs revision:
https://github.com/NixOS/nixpkgs/commit/c172f144f405 kdeApplications:
Use latest qt515 by default
This commit updates the version of Qt used to build the KDE Frameworks
and Applications from 5.14.x to 5.15.0 .

However, that commit doesn't affect Kate; I bisected again to find
https://github.com/NixOS/nixpkgs/commit/0263f626a060 qt-5: 5.15.0 -> 5.15.2
Which causes the same behaviour change for Kate.

Initially I was confused as to why a Qt version update should affect
this, as I assumed the functionality was provided by KDE Frameworks,
but it looks like Qt provides a menu accelerator class, so perhaps
that's at the bottom of the stack here. It's worth noting that in the
versions of Okular/Kate with the press behaviour, the accelerator
underlines are permanently visible, which is probably related.

For what it's worth, my copy of Firefox doesn't require a hold, but my
copy of Libreoffice does, so I guess there isn't much of a standard.
Anyway - I can't tell whether this is an intended change, so I'd love
to hear from someone who knows.

Kind Regards,
Craig Hall