I'm afraid I have to ask again, are you not concerned with the fact that scripts already use $null value from $sfile to indicate that the user canceled the selection dialog?
Right now a $null value returned from $sfile because of 'reserved' folder is going to be taken as a cancel, and rightfully so.
In others words, there is no way to tell the difference between the user canceling with the mouse/keyboard and the folder being a reserved folder.
Not only it's breaking backward compatibilities but the behavior itself doesn't help us because we can't even tell either that a reserved folder was reached (regardless of users's canceling).
Please consider returning plain text $error or any other similar value that would indicate a reserved folder was reached, or at least please explain the reasoning of this choice.
