Merge branch '2535_ftp_segfault'

* 2535_ftp_segfault:
  Check whether VFS provides an open_archive() method.
  Ticket #2535: segfault in FTP VFS

lib/vfs/direntry.c

@@ -1067,6 +1067,7 @@ vfs_s_get_path_mangle (struct vfs_class *me, char *inname, struct vfs_s_super **
         ERRNOR (EIO, NULL);
 
     super = vfs_s_new_super (me);
+    if (MEDATA->open_archive != NULL)
         result = MEDATA->open_archive (me, super, archive_name, op);
     if (result == -1)
     {
@@ -1198,6 +1199,7 @@ vfs_s_open (struct vfs_class *me, const char *file, int flags, mode_t mode)
     fh->handle = -1;
     fh->changed = was_changed;
     fh->linear = 0;
+    fh->data = NULL;
 
     if (IS_LINEAR (flags))
     {