* environ.cc (set_winsymlinks): Handle "winsymlinks:nativestrict"

option.  On pre-Vista warn the user if the "winsymlinks:native*" option
	is set.
	* globals.cc (enum winsym_t): Add WSYM_nativestrict.
	* path.cc (symlink_native): Don't create native symlink if target
	does not exist.  Explain why.  Improve comments.
	(symlink_worker): Change AFS symlink handling to WSYM_nativestrict.
	Handle WSYM_nativestrict throughout.  Change condition for bail out
	to wsym_type == WSYM_nativestrict.  Add comment.  Fix formatting.
	* shared_info.h (CURR_USER_MAGIC): Change to reflect change in
	class user_info.
	(class user_info): Add member warned_nonativesyms.

winsup/cygwin/ChangeLog

@@ -1,3 +1,18 @@
+2013-05-23  Corinna Vinschen  <corinna@vinschen.de>
+
+	* environ.cc (set_winsymlinks): Handle "winsymlinks:nativestrict"
+	option.  On pre-Vista warn the user if the "winsymlinks:native*" option
+	is set.
+	* globals.cc (enum winsym_t): Add WSYM_nativestrict.
+	* path.cc (symlink_native): Don't create native symlink if target
+	does not exist.  Explain why.  Improve comments.
+	(symlink_worker): Change AFS symlink handling to WSYM_nativestrict.
+	Handle WSYM_nativestrict throughout.  Change condition for bail out
+	to wsym_type == WSYM_nativestrict.  Add comment.  Fix formatting.
+	* shared_info.h (CURR_USER_MAGIC): Change to reflect change in
+	class user_info.
+	(class user_info): Add member warned_nonativesyms.
+
 2013-05-22  Corinna Vinschen  <corinna@vinschen.de>
 
 	* spinlock.h (ULONG): Replace LONG operator with ULONG to accommodate

winsup/cygwin/environ.cc

@@ -97,9 +97,22 @@ set_winsymlinks (const char *buf)
   else if (ascii_strncasematch (buf, "lnk", 3))
     allow_winsymlinks = WSYM_lnk;
   /* Make sure to try native symlinks only on systems supporting them. */
-  else if (ascii_strncasematch (buf, "native", 6)
-	   && wincap.max_sys_priv () >= SE_CREATE_SYMBOLIC_LINK_PRIVILEGE)
-    allow_winsymlinks = WSYM_native;
+  else if (ascii_strncasematch (buf, "native", 6))
+    {
+      if (wincap.max_sys_priv () < SE_CREATE_SYMBOLIC_LINK_PRIVILEGE)
+	{
+	  if (!user_shared->warned_nonativesyms)
+	    {
+	      small_printf ("\"winsymlinks:%s\" option detected in CYGWIN environment variable.\n"
+			    "Native symlinks are not supported on Windows versions prior to\n"
+			    "Windows Vista/Server 2008.  This option will be ignored.\n", buf);
+	      user_shared->warned_nonativesyms = 1;
+	    }
+	}
+      else
+	allow_winsymlinks = ascii_strcasematch (buf + 6, "strict")
+			    ? WSYM_nativestrict : WSYM_native;
+    }
 }
 
 /* The structure below is used to set up an array which is used to

winsup/cygwin/globals.cc

@@ -56,6 +56,7 @@ enum winsym_t
   WSYM_sysfile = 0,
   WSYM_lnk,
   WSYM_native,
+  WSYM_nativestrict,
   WSYM_nfs
 };
 

winsup/cygwin/path.cc

@@ -1542,9 +1542,19 @@ symlink_native (const char *oldpath, path_conv &win32_newpath)
       final_oldpath = win32_oldpath.get_nt_native_path ();
       final_oldpath->Buffer += dirpath.Length / sizeof (WCHAR);
     }
+  /* If the symlink target doesn't exist, don't create native symlink.
+     Otherwise the directory flag in the symlink is potentially wrong
+     when the target comes into existence, and native tools will fail.
+     This is so screwball. This is no problem on AFS, fortunately. */
+  if (!win32_oldpath.exists () && !win32_oldpath.fs_is_afs ())
+    {
+      SetLastError (ERROR_FILE_NOT_FOUND);
+      return -1;
+    }
+  /* Convert native path to DOS UNC path. */
   final_newpath = win32_newpath.get_nt_native_path ();
-  /* Convert native to DOS UNC path. */
   final_newpath->Buffer[1] = L'\\';
+  /* Try to create native symlink. */
   if (!CreateSymbolicLinkW (final_newpath->Buffer, final_oldpath->Buffer,
 			    win32_oldpath.isdir ()
 			    ? SYMBOLIC_LINK_FLAG_DIRECTORY : 0))
@@ -1618,10 +1628,10 @@ symlink_worker (const char *oldpath, const char *newpath, bool isdevice)
 	  set_errno (EPERM);
 	  goto done;
 	}
-      wsym_type = WSYM_native;
+      wsym_type = WSYM_nativestrict;
     }
   /* Don't try native symlinks on filesystems not supporting reparse points. */
-  else if (wsym_type == WSYM_native
+  else if ((wsym_type == WSYM_native || wsym_type == WSYM_nativestrict)
 	   && !(win32_newpath.fs_flags () & FILE_SUPPORTS_REPARSE_POINTS))
     wsym_type = WSYM_sysfile;
 
@@ -1662,13 +1672,17 @@ symlink_worker (const char *oldpath, const char *newpath, bool isdevice)
       res = symlink_nfs (oldpath, win32_newpath);
       goto done;
     case WSYM_native:
+    case WSYM_nativestrict:
       res = symlink_native (oldpath, win32_newpath);
-      /* AFS?  Too bad.  Otherwise, just try the default symlink type. */
-      if (win32_newpath.fs_is_afs ())
+      if (!res)
+      	goto done;
+      /* Strictly native?  Too bad. */
+      if (wsym_type == WSYM_nativestrict)
 	{
 	  __seterrno ();
 	  goto done;
 	}
+      /* Otherwise, fall back to default symlink type. */
       wsym_type = WSYM_sysfile;
       break;
     default:
@@ -1853,7 +1867,8 @@ symlink_worker (const char *oldpath, const char *newpath, bool isdevice)
        so for now we don't request WRITE_DAC on remote drives. */
     access |= READ_CONTROL | WRITE_DAC;
 
-  status = NtCreateFile (&fh, access, win32_newpath.get_object_attr (attr, sec_none_nih),
+  status = NtCreateFile (&fh, access,
+			 win32_newpath.get_object_attr (attr, sec_none_nih),
 			 &io, NULL, FILE_ATTRIBUTE_NORMAL,
 			 FILE_SHARE_VALID_FLAGS,
 			 isdevice ? FILE_OVERWRITE_IF : FILE_CREATE,

winsup/cygwin/shared_info.h

@@ -15,7 +15,7 @@ details. */
 #include "limits.h"
 #include "mount.h"
 
-#define CURR_USER_MAGIC 0x6467403bU
+#define CURR_USER_MAGIC 0xab1fcce8U
 
 class user_info
 {
@@ -25,6 +25,7 @@ public:
   DWORD cb;
   bool warned_msdos;
   bool warned_notty;
+  bool warned_nonativesyms;
   mount_info mountinfo;
   friend void dll_crt0_1 (void *);
   static void create (bool);