I will wait for someone from the frameworks team to review this before landing it.

Sounds good. It's the same thing that's done in other places, so I don't expect there'll be any problem.

Wait, do we need to add this workaround to every popup menu around? What about 3d-party apps?

Can't we fix the actual bug in Qt/breeze/whatever instead?

@anemeth can provide the details, but IIRC we did wind up concluding that we needed this workaround in various places.

In D18798#407428, @elvisangelaccio wrote:

Wait, do we need to add this workaround to every popup menu around? What about 3d-party apps?

Can't we fix the actual bug in Qt/breeze/whatever instead?

I believe this is a bug in Breeze, since this works with Kvantum themes without this.
We had this discussion in https://bugs.kde.org/show_bug.cgi?id=395262
I know this is not the best approach, but it's easier to fix it in the most obvious places instead of rewriting Breeze
This fixes the DnD menu on the desktop and in Dolphin as well

In D18798#407428, @elvisangelaccio wrote:

Wait, do we need to add this workaround to every popup menu around? What about 3d-party apps?

Definitely not an option. IMHO it makes no nsense to add these lines in every single Qt application.

Can't we fix the actual bug in Qt/breeze/whatever instead?

Exactly. Please fix breeze instead.

The workaround isn't required everywhere, just in a small number of places. This is actually the last place that causes user-facing issues with blur that I'm aware of, and prior patches were accepted by Plasma developers, so it would be a shame not to land this last one.

In D18798#413803, @ngraham wrote:

The workaround isn't required everywhere, just in a small number of places.

It still is a workaround, and the fact that the places where this is "needed" are not many still does not justify it IMHO.

prior patches were accepted by Plasma developers, so it would be a shame not to land this last one.

The real shame was to accept such workarounds in other places, instead of fixing breeze (or qt).

Again, -1 for workarounds in important places like KIO, where they will stay for years because people forget about them...

@pino, can you help fix us the root cause then? The reason why we've resorted to these workarounds is because nobody's been able to adequately understand the root cause or implement a risk-free fix.