ports/184039: Mk/Scripts: fix working with blanks in filenames, handle missing variables

[edwin at FreeBSD.org]

Synopsis: Mk/Scripts: fix working with blanks in filenames, handle missing variables

State-Changed-From-To: open->feedback
State-Changed-By: edwin
State-Changed-When: Sun Nov 17 20:20:07 UTC 2013
State-Changed-Why: 
Awaiting maintainers feedback (via the GNATS Auto Assign Tool)

http://www.freebsd.org/cgi/query-pr.cgi?pr=184039