cocoa.dialogs: simple fix for split-path errors with empty string input.
cocoa.dialogs: simple fix for split-path errors with empty string input.

mrjbq7/factor,bpollack/factor,bpollack/factor,factor/factor,factor/factor,bpollack/factor,tgunr/factor,bpollack/factor,AlexIljin/factor,bpollack/factor,AlexIljin/factor,AlexIljin/factor,tgunr/factor,factor/factor,factor/factor,AlexIljin/factor,tgunr/factor,factor/factor,AlexIljin/factor,bpollack/factor,mrjbq7/factor,AlexIljin/factor,mrjbq7/factor,factor/factor,AlexIljin/factor,mrjbq7/factor,tgunr/factor,mrjbq7/factor,mrjbq7/factor,tgunr/factor,tgunr/factor,bpollack/factor