"Switch applications" and all Windows/Launchers actions work only with Alt

[Tassilo Horn <tassilo member fsf org>]

Hi all,

I've just noticed that when assigning shortcuts to actions in the
Keyboard settings, there are quite some actions that can only be
triggered if the shortcut includes the Alt modifier.  This is not
documented anywhere, and IMO it clearly classifies as a bug.

For example, try assigning

  Navigation > Switch applications to Mod4+Tab

This somehow works, but has a completely different behavior than the
action that is triggered for the standard Alt+Tab shortcut. With
Mod4+Tab, it toggles between the current and the last recently used
window and there is no application onscreen dialog at all.  But any
keyboard shortcut that includes Alt, e.g., Alt+Mod4+Tab, works as
expected.

A similar issue applies to all actions in the Windows category or in the
Launchers category.  All these actions (Minimize window, Maximize
window, Close window, ..., Launch help browser, Home folder, ...) are
only triggered, if the Alt modifier is used in the shortcut.

Is that a bug, or is there a reason of hard-coding Alt?  If it is a bug,
I'd go and report it.  But what's the right component?  gnome-shell?
mutter?  metacity?

Bye,
Tassilo