Panel appears over fullscreen windows when switching workspaces

[Archenoth]

When a window is fullscreen on a workspace, the panel is hidden below the window. This is good.
When you switch workspaces, and switch back, it remains hidden. This is also good.
But, when you try this with two monitors, the panel appears above the fullscreen window. This is not.

You can see the panel is blocking the Emacs Modeline on my first monitor here:

This happens reliably every workspace switch, and it happens regardless of the contents of the second monitor. (So, it happens when the fullscreen application is the only thing open.)

You can fix it by unfocusing the window... (Which seems to inadvertently happen when taking a screenshot.)

This is with Cinnamon version 2.6.11+rafaela.

[Archenoth]

As a bit of an update... The workaround to hide the menubar I mentioned above does not appear to work when the fullscreen window is the only window open on any workspace.

Instead, you have to take the window out of fullscreen and put it back in again.

(Checked with 2.6.13)

[Archenoth]

I also found out that [Ctrl] + [Backspace] works as another workaround. (I wonder why those two keys in particular?)

[Archenoth]

Since this is mildly infuriating, and because the key-combo workarounds fail now... Here is what I use as an Emacs hook to keep it in the foreground.

(add-hook 'focus-in-hook (lambda ()
                           (lower-frame)
                           (raise-frame)))

While this is application-specific, it probably gives a hint as to what is wrong... (Since I am just unfocusing and focusing in the frame again)

[JosephMcc]

Should be fixed by #5229