* fhandler.cc (fhandler_base::open): When creating a file on a

filesystem supporting ACLs, create the file with WRITE_DAC access.
	Explain why.
	* fhandler_disk_file.cc (fhandler_disk_file::mkdir): Ditto for
	directories.
	* fhandler_socket.cc (fhandler_socket::bind): Ditto for sockets.
	* path.cc (symlink_worker): Ditto for symlinks.
	* security.cc (get_file_sd): Always call GetSecurityInfo for directories
	on XP and Server 2003.  Improve comment to explain why.
	(set_file_attribute): Explicitely cast mode_t value to bool in call to
	get_file_sd.
	* wincap.h (wincaps::use_get_sec_info_on_dirs): New element.
	* wincap.cc: Implement above element throughout.

winsup/cygwin/fhandler.cc

@@ -577,6 +577,13 @@ fhandler_base::open (int flags, mode_t mode)
 	    /* If mode has no write bits set, and ACLs are not used, we set
 	       the DOS R/O attribute. */
 	    file_attributes |= FILE_ATTRIBUTE_READONLY;
+	  else if (!exists () && has_acls ())
+	    /* If we are about to create the file and the filesystem supports
+	       ACLs, we will overwrite the DACL after the call to NtCreateFile.
+	       This requires a handle with additional WRITE_DAC access,
+	       otherwise set_file_sd has to open the file again. */
+	    access |= WRITE_DAC;
+
 	  /* The file attributes are needed for later use in, e.g. fchmod. */
 	  pc.file_attributes (file_attributes);
 	}