Experimenting with bug 1002602, I found a workaround for this.
If you don't need the decoation bar:
Set "Decoration Windows" to "none"
Leave other settings as they are.
The window menu (alt+right click or space) will be available.
Windows will also have shadows for borders.
If you don't need shadows or any kind of border:
Adjust the settings for "Active/Inactive Shadow"
Leave "Shadow windows" set to "any"
Without this, the decorator will not run, ergo no window menu.
Experimenting with bug 1002602, I found a workaround for this.
If you don't need the decoation bar:
Set "Decoration Windows" to "none"
Leave other settings as they are.
The window menu (alt+right click or space) will be available.
Windows will also have shadows for borders.
If you don't need shadows or any kind of border:
Adjust the settings for "Active/Inactive Shadow"
Leave "Shadow windows" set to "any"
Without this, the decorator will not run, ergo no window menu.