Ticket #3016: Segfault while entering into extfs archive

Current master (4.8.8-49-g6b64835) segfaults while entering into any extfs archive (zip, rar, etc).
Bad commit is 2640b21bb9700aa51a70f35f9e10732c82a7366f.

Signed-off-by: Slava Zanko <slavazanko@gmail.com>

src/vfs/extfs/extfs.c

@@ -666,6 +666,7 @@ extfs_which (struct vfs_class *me, const char *path)
 static const char *
 extfs_get_path_int (const vfs_path_t * vpath, struct archive **archive, gboolean do_not_open)
 {
+    char *archive_name;
     int result = -1;
     struct archive *parc;
     int fstype;
@@ -677,6 +678,8 @@ extfs_get_path_int (const vfs_path_t * vpath, struct archive **archive, gboolean
     if (fstype == -1)
         return NULL;
 
+    archive_name = vfs_path_to_str_elements_count (vpath, -1);
+
     /*
      * All filesystems should have some local archive, at least
      * it can be PATH_SEP ('/').
@@ -684,14 +687,15 @@ extfs_get_path_int (const vfs_path_t * vpath, struct archive **archive, gboolean
     for (parc = first_archive; parc != NULL; parc = parc->next)
         if (parc->name != NULL)
         {
-            if (strcmp (parc->name, vfs_path_as_str (vpath)) == 0)
+            if (strcmp (parc->name, archive_name) == 0)
             {
                 vfs_stamp (&vfs_extfs_ops, (vfsid) parc);
                 goto return_success;
             }
         }
 
-    result = do_not_open ? -1 : extfs_read_archive (fstype, vfs_path_as_str (vpath), &parc);
+    result = do_not_open ? -1 : extfs_read_archive (fstype, archive_name, &parc);
+    g_free (archive_name);
     if (result == -1)
     {
         path_element->class->verrno = EIO;