* grub-core/lib/arg.c (grub_arg_show_help): Fix a NULL pointer

dereference.
	Reported by: qwertial.

ChangeLog

@@ -1,3 +1,9 @@
+2013-04-29  Vladimir Serbinenko  <phcoder@gmail.com>
+
+	* grub-core/lib/arg.c (grub_arg_show_help): Fix a NULL pointer
+	dereference.
+	Reported by: qwertial.
+
 2013-04-28  Vladimir Serbinenko  <phcoder@gmail.com>
 
 	* docs/grub.texi: Add a comment about usefullness of nativedisk.

grub-core/lib/arg.c

@@ -158,7 +158,7 @@ grub_arg_show_help (grub_extcmd_t cmd)
   show_usage (cmd);
   grub_printf ("%s\n\n", _(cmd->cmd->description));
 
-  for (opt = cmd->options; opt->doc; opt++)
+  for (opt = cmd->options; opt && opt->doc; opt++)
     switch (opt->shortarg)
       {
       case 'h':