> ------------------------------------------------------------
> revno: 3148.9.3
> revision-id: azundris@mysql.com-20091029230154-jp2xqvzw2nhj9q41
> parent: azundris@mysql.com-20091027095316-54lwjr9vqkscq1ik
> committer: Tatiana A. Nurnberg <azundris@mysql.com>
> branch nick: 51-48295
> timestamp: Thu 2009-10-29 16:01:54 -0700
> message:
>   Bug#48295: explain extended crash with subquery and ONLY_FULL_GROUP_BY sql_mode
>   
>   If an outer query is broken, a subquery might not even get set up.
>   EXPLAIN EXTENDED did not expect this and merrily tried to de-ref all
>   of the half-setup info.
>   
>   We now catch this case and print as much as we have, as it doesn't cost us
>   anything (doesn't make regular execution slower).