Modifier keys selecting dropEffect with 'copyMove'

1. Drag the orange square over the blue square
2. Press the relevant modifier keys for your platform
3. Continue dragging over the pink square
4. Release the drag, then the keys
5. Check that the correct drop effect is produced in each case. If the mouse cursor can change to indicate the final type of drop effect that will take place, it should change to the relevant type (the one in bold) once the modifier keys are pressed.

Windows
Modifier | Drop effect
--- | ---
None | copy
Ctrl | copy
Shift | copy=>move
Alt | copy=>link=>none
Ctrl+Shift | copy=>link=>none
Ctrl+Alt | copy
Alt+Shift | copy
Ctrl+Alt+Shift | copy

Unix/Linux
Modifier | Drop effect
--- | ---
none | copy
Ctrl | copy
Shift | copy=>move
Alt | copy
Ctrl+Shift | copy=>link=>none
Ctrl+Alt | copy
Alt+Shift | copy=>move
Ctrl+Alt+Shift | copy=>link=>none

Mac
Modifier | Drop effect
--- | ---
none | copy
Ctrl | copy
Shift | copy
Option/alt | copy
Command | copy=>move
Ctrl+Shift | copy
Ctrl+Option | copy
Ctrl+Command | copy=>move
Shift+Option | copy
Shift+Command | copy=>move
Command+Option | copy=>link=>none
Ctrl+Shift+Option | copy
Ctrl+Shift+Command | copy=>move
Ctrl+Command+Option | copy=>link=>none
Shift+Command+Option | copy=>link=>none
Ctrl+Shift+Command+Option | copy=>link=>none