Support symlinks on latest versions of MS-Windows.

 src/w32.c: Include winioctl.h and aclapi.h.
 (is_symlink, chase_symlinks, enable_privilege, restore_privilege)
 (revert_to_self): Forward declarations of static functions.
 <static BOOL g_b_init_get_security_info>:
 <g_b_init_create_symbolic_link>: New static flags.
 (globals_of_w32): Initialize them to zero.
 (GetSecurityInfo_Proc, CreateSymbolicLink_Proc): New typedefs.
 (map_w32_filename): Improve commentary.  Simplify switch.
 (SYMBOLIC_LINK_FLAG_DIRECTORY): Define if not defined in system
 headers (most versions of MinGW w32api don't).
 (get_security_info, create_symbolic_link)
 (get_file_security_desc_by_handle, is_symlink, chase_symlinks):
 New functions.
 (sys_access, sys_chmod): Call 'chase_symlinks' to resolve symlinks
 in the argument file name.
 (sys_access): Call unc_volume_file_attributes only if
 GetFileAttributes fails with network-related error codes.
 (sys_rename): Diagnose renaming of a symlink when the user doesn't
 have the required privileges.
 (get_file_security_desc_by_name): Renamed from
 get_file_security_desc.
 (stat_worker): New function, with most of the guts of 'stat', and
 with addition of handling of symlinks and support for 'lstat'.  If
 possible, get file's attributes and security information by
 handle, not by name.  Produce S_IFLNK bit for symlinks, when
 called from 'lstat'.
 (stat, lstat): New functions, call 'stat_worker'.
 (symlink, readlink, careadlinkat): Rewritten to create and resolve
 symlinks when the underlying filesystem supports them.

 lib/src/ntlib.c (lstat): New function, calls 'stat'.

 nt/inc/sys/stat.h (S_IFLNK): Define.
 (S_ISLNK): A non-trivial definition.
 (lstat): Prototype instead of a macro that redirects to 'stat'.

 lisp/files.el (file-truename): Don't skip symlink-chasing part on
 windows-nt.  Incorporate the resolution of 8+3 short aliases on
 Windows into the loop that recursively chases symlinks.  Compare
 directory and its parent case-insensitively on MS-Windows and
 MS-DOS.

 etc/NEWS: Announce the symlink support on MS-Windows.

2 files changed, 10 insertions, 5 deletions

diff --git a/nt/ChangeLog b/nt/ChangeLog
index 8b9163c9f78..d8b9b14a3fb 100644
--- a/nt/ChangeLog
+++ b/nt/ChangeLog
@@ -1,3 +1,9 @@
+2012-08-03  Eli Zaretskii  <eliz@gnu.org>
+
+	* inc/sys/stat.h (S_IFLNK): Define.
+	(S_ISLNK): A non-trivial definition.
+	(lstat): Prototype instead of a macro that redirects to 'stat'.
+
 2012-08-02  Paul Eggert  <eggert@cs.ucla.edu>
 
 	Use C99-style 'extern inline' if available.
diff --git a/nt/inc/sys/stat.h b/nt/inc/sys/stat.h
index 57fabff4b0c..b673b80a0e3 100644
--- a/nt/inc/sys/stat.h
+++ b/nt/inc/sys/stat.h
@@ -33,13 +33,14 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <sys/types.h>
 #include <time.h>
 
-#define	S_IFMT	0xF000
+#define	S_IFMT	0xF800
 
 #define	S_IFREG	0x8000
 #define	S_IFDIR	0x4000
 #define	S_IFBLK	0x3000
 #define	S_IFCHR	0x2000
 #define	S_IFIFO	0x1000
+#define	S_IFLNK 0x0800
 
 #define	S_IREAD	 0x0100
 #define	S_IWRITE 0x0080
@@ -55,6 +56,7 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define	S_ISBLK(m)	(((m) & S_IFMT) == S_IFBLK)
 #define	S_ISCHR(m)	(((m) & S_IFMT) == S_IFCHR)
 #define	S_ISFIFO(m)	(((m) & S_IFMT) == S_IFIFO)
+#define	S_ISLNK(m)	(((m) & S_IFMT) == S_IFLNK)
 
 /* These don't exist on Windows, but lib/filemode.c wants them.  */
 #define S_ISUID 0
@@ -68,7 +70,6 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #define S_IXOTH (S_IXUSR >> 6)
 
 #define S_ISSOCK(m)    0
-#define S_ISLNK(m)     0
 #define S_ISCTG(p)     0
 #define S_ISDOOR(m)    0
 #define S_ISMPB(m)     0
@@ -103,9 +104,7 @@ struct stat {
 _CRTIMP int __cdecl __MINGW_NOTHROW	fstat (int, struct stat*);
 _CRTIMP int __cdecl __MINGW_NOTHROW	chmod (const char*, int);
 _CRTIMP int __cdecl __MINGW_NOTHROW	stat (const char*, struct stat*);
-
-/* fileio.c and dired.c want lstat.  */
-#define lstat stat
+_CRTIMP int __cdecl __MINGW_NOTHROW	lstat (const char*, struct stat*);
 
 #endif	/* INC_SYS_STAT_H_ */