[Rd] basename returns "." not in filename (PR#13958)

[joehl at web.de]

Full_Name: Jens Oehlschlägel
Version: 2.9.2
OS: Win32
Submission from: (NULL) (85.181.152.156)


# Obviously an empty basename is allowed (if the filepath is a pure path)
> basename("/")
[1] ""

# but here we get the dot from the path
> basename("./")
[1] "."

> version
               _                           
platform       i386-pc-mingw32             
arch           i386                        
os             mingw32                     
system         i386, mingw32               
status                                     
major          2                           
minor          9.2                         
year           2009                        
month          08                          
day            24                          
svn rev        49384                       
language       R                           
version.string R version 2.9.2 (2009-08-24)