id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
13428,"Windows: ""is_symlink"" for drive letter (without trailing directory separator) returns the wrong result",m.kosch@…,Beman Dawes,"Suppose you have a normal directory {{{Dir}}} and a symlink named {{{SymlinkToDir}}} which points to {{{Dir}}} on drive {{{C:\}}}.

The following two tests lead to different results:
{{{
boost::filesystem::path fsPathToSymlink(""C:\\SymlinkToDir"");
boost::filesystem::path fsPathToDrive(""C:"");

current_path(fsPathToDrive + ""\\"");
bool b1 = is_symlink(fsPathToDrive);
assert( b1 == false );

current_path(fsPathToSymlink);
bool b2 = is_symlink(fsPathToDrive);
assert( b2 == true );
}}}

It seems that Windows differentiates between {{{C:}}} and {{{C:\}}}. The first form seems to denote the current directory on drive {{{C:\}}} while the second form seems to denote drive {{{C:\}}} itself. This also can be observed in the Windows command promt.

{{{is_symlink}}} internally uses {{{GetFileAttributesW}}} to determine the symlink status. {{{GetFileAttributes(""C:"")}}} returns the file attributes of {{{C:\\SymlinkToDir}}} instead of {{{C:\}}}.

The function {{{is_symlink}}} is used to implement other functions, so this problem also effects at least the following other functions, possibly even many more:

* {{{canonical}}} returns {{{BOOST_ERROR_NOT_SUPPORTED}}} for an absolute path, if compiled for Windows versions earlier than Windows Vista ({{{_WIN32_WINNT < 0x0600}}}) and the current directory represents a symlink.

* {{{weakly_canonical}}} in the same scenario as above, because this utilizes {{{canonical}}}.",Bugs,new,To Be Determined,filesystem,Boost 1.66.0,Problem,,symlink is_symlink canonical weakly_canonical GetFileAttributes GetFileAttributesW,m.kosch@…