<primary><super> settable in key bindings but not usable in editor pane

[philiprbrenan]

primary+ super can be set without a following character in key bindings but does not do anything in the editor pane:

[elextr]

Confirmed, the key combo is invalid (both keys are modifiers) but preferences keybinding dialog doesn't check, should call gtk_accelerator_valid().

[eht16]

Interestingly, for me it seems the Super key is named "Super_L" and most importantly can be used as a single key. The keybinding Primary+Super_L actually works on its own.
Once I would add a third key to the comvination, the Super key will get a modifier but on the combination of two modifiers, it is a single key.

So, on my system, the current behaviour seems correct to me.
It just raises the question why is this behaviour different and what components have any impact on it?

[elextr]

Here its also called Super-L (and Super_R) by itself, but I can't set it by itself as its stolen by the Cinnamon desktop to show its menu.

Also Ctrl_L (and Ctrl_R) can be set by themselves (and work).

But the combination <Primary>Super_L/R can be set but does not work, nor does it do anything in the desktop, but maybe its still being stolen by it.

But <primary><super>a can be set and works.

But the OP is getting <primary><super> which is two modifiers, @philiprbrenan @eht16 whats your Geany and GTK and OS and desktop version information?

Here is Cinnamon desktop and

11:12:18: Geany INFO		: Geany 1.38 (git >= b524a58e), en_AU.UTF-8
11:12:18: Geany INFO		: GTK 3.24.20, GLib 2.64.6
11:12:18: Geany INFO		: OS: Linux Mint 20 (ulyana)

[eht16]

But the combination <Primary>Super_L/R can be set but does not work, nor does it do anything in the desktop, but maybe its still being stolen by it.

I guess so, it seems reasonable that the WM eats this combination and so it seems to not work.

But <primary><super>a can be set and works.

But the OP is getting <primary><super> which is two modifiers, @philiprbrenan @eht16 whats your Geany and GTK and OS and desktop version information?

That's true. No idea what's the difference.
I'm using Xfce 4.16 with:

23:32:49: Geany INFO		: Geany 1.38 (git >= b524a58e), en_US.utf8
23:32:49: Geany INFO		: GTK 3.24.29, GLib 2.68.2
23:32:49: Geany INFO		: OS: Arch Linux