Select/Deselect All should be disabled if I cannot (de)select something

After choosing the install path I'm getting the possibility to choose the components to install. (DeselectAll.png)

Clicking on 'Deselect All' does nothing except that 'Deselect All' becomes disabled and 'Select All' becomes enabled. (SelectAll.png)

Clicking now 'Select All' does nothin except that 'Select All' becomes disabled and 'Deselect All' becomes enabled again. (DeselectAll.png)

I'd prefer to disable both if there's nothing I can check or uncheck.