[Rd] file.link on Windows 7

[Rui Barradas]

Hello,

A post to R-Help by Oliver Soong reports what seems to be a bug specific 
to Windows (I'm on Windows 7).
The original post is as follows:

----------------------------------------------------------------
from: Oliver Soong <osoong+r at gmail.com>
to: r-help <r-help at r-project.org>
date: Fri, 7 Dec 2012 22:07:49 -0800
subject: [R] file.link fails on NTFS

Windows 7 64-bit, R 2.15.2 i386.  Working directory is on an NTFS drive.

> writeLines("", "file.txt")
> file.link("file.txt", "link.txt")

Warning in file.link("file.txt", "link.txt") :
   cannot link 'link.txt' to 'link.txt', reason 'The system cannot find
the file specified'

No link is created.  The 'link.txt' to 'link.txt' is suspicious.  Does
this happen to anybody else?  I didn't find anything in my searches.

Oliver

----------------------------------------------------------------
The above code runs with no problems on Ubuntu 12.04/ R 2.15.2, 
file.link returns TRUE.
I've checked the sources and .Internal calls "file.link", executing 
do_filelink(). The segment in file src/main/platform.c seems right, not 
mistaking argument 'from' for 'to':

#ifdef Win32
         wchar_t *from, *to;

         from = filenameToWchar(STRING_ELT(f1, i%n1), TRUE);
         to = filenameToWchar(STRING_ELT(f2, i%n2), TRUE);
         LOGICAL(ans)[i] = CreateHardLinkW(to, from, NULL) != 0;
         if(!LOGICAL(ans)[i]) {
         warning(_("cannot link '%ls' to '%ls', reason '%s'"),
             from, to, formatError(GetLastError()));
         }
#else


But there's something going on. The link is not created and the warning 
message is wrong.

Bug report? (Why CreateHardLinkW, and not CreateHardLink?)

Rui Barradas