1. Have Meta+D bound to the "Show desktop" command.
2. Have the desktop show a directory view
3. Minimize all other windows, unminimize a dolphin window and ensure it has keyboard focus
4. Press Meta+D which should give the desktop the keyboard focus
5. Press Meta+D again, it should give keyboard focus back to the dolphin window but it doesn't.
The problem is not specific to dolphin of course. There is some "wonkiness" in this area and keyboard focus doesn't move as you would expect when you activate "Show desktop."
Cannot reproduce with current git master. This always works for me. Assuming it was fixed at some point.