'info non_existing_info_page -o -' (or 'info non_existing_info_page -o somefile') segfaults

[Vitezslav Crhonek]

Hi,

running:

# info non_existing_info_page -o

or

# info non_existing_info_page -o somefile

ends with segmentation fault with latest upstream release
(texinfo-5.2).

The issue is in window_set_node_of_window() where NULL 'window'
variable is dereferenced. Same threat is present in
display_update_one_window() with 'win' variable.

Previously (texinfo-4.13a), info finished gracefully and
returned:
# info non_existing_info_page -o -
info: No menu item `non_existing_info_page' in node `(dir)Top'.

I have some patches to fix the issue, but none of them
is behaving like in the previous versions. The closest one
is attached (but it produces also blank space and
does not terminate the last line...).

Best regards,
Vitezslav Crhonek

diff -up texinfo-5.2/info/info.c.orig texinfo-5.2/info/info.c
--- texinfo-5.2/info/info.c.orig        2013-08-22 19:54:06.000000000 +0200
+++ texinfo-5.2/info/info.c     2014-01-15 13:52:10.778839560 +0100
@@ -237,7 +237,10 @@ single_file (char *filename, int argc, c
   if (user_output_filename && !goto_invocation_p)
     {
       if (error_node)
-       show_error_node (error_node);
+       {
+         initialize_info_session (error_node, 0);
+         show_error_node (error_node);
+       }
       else
        dump_node_to_file (initial_node, user_output_filename,
                           dump_subnodes);