Re: pg_trigger.tgargs needs detoast

Patch applied.  Thanks.

Backpached to 8.2.X.  If it needs to be backpatched to older releases,
someone needs to research that.

---------------------------------------------------------------------------



Kenji Kawamura wrote:
>    Hello,
> 
>    This patch fixes a bug of case of extraction of pg_trigger.tgargs.
>    There was a problem when we used a long argument in defining trigger,
> possibly resulting in a server crash.
> 
> Example:
> 
>    We defined a CREATE TRIGGER such as follows and registered trigger.
>    In this case, the argument value which we received in the trigger
> procedure was not right.
> 
> CREATE TRIGGER trigger_test BEFORE INSERT OR UPDATE ON sample FOR EACH
> ROW EXECUTE PROCEDURE sample_trig('XXX...(more than 1823 characters)');
> 
>    The trigger procedure which receives the argument:
> 
> Datum sample_trig(PG_FUNCTION_ARGS)
> {    
>     TriggerData* trigdata = (TriggerData*)fcinfo->context;
>     char** args = trigdata->tg_trigger->tgargs;
>     int nargs = trigdata->tg_trigger->tgnargs;
> 
>     int i;
>     for (i = 0; i < nargs; i++) {
>         elog(LOG, "%s", args[i]);
>     }
>     ...
> }
> 
> Result:
> 
>    Before: LOG: (the character that is not right, for example '%')
>    After : LOG: XXX...(more than 1823 characters)
> 
> Regards,
> 
> ---
> Kenji Kawamura
> NTT Open Source Center, Japan
> 

> Index: src/backend/commands/tablecmds.c
> ===================================================================
> --- src/backend/commands/tablecmds.c    (HEAD)
> +++ src/backend/commands/tablecmds.c    (modified)
> @@ -1800,8 +1800,7 @@
>           * line; so does trigger.c ...
>           */
>          tgnargs = pg_trigger->tgnargs;
> -        val = (bytea *)
> -            DatumGetPointer(fastgetattr(tuple,
> +        val = DatumGetByteaP(fastgetattr(tuple,
>                                          Anum_pg_trigger_tgargs,
>                                          tgrel->rd_att, &isnull));
>          if (isnull || tgnargs < RI_FIRST_ATTNAME_ARGNO ||
> Index: src/backend/commands/trigger.c
> ===================================================================
> --- src/backend/commands/trigger.c    (HEAD)
> +++ src/backend/commands/trigger.c    (modified)
> @@ -906,8 +906,7 @@
>              char       *p;
>              int            i;
>  
> -            val = (bytea *)
> -                DatumGetPointer(fastgetattr(htup,
> +            val = DatumGetByteaP(fastgetattr(htup,
>                                              Anum_pg_trigger_tgargs,
>                                              tgrel->rd_att, &isnull));
>              if (isnull)
> Index: src/backend/utils/adt/ruleutils.c
> ===================================================================
> --- src/backend/utils/adt/ruleutils.c    (HEAD)
> +++ src/backend/utils/adt/ruleutils.c    (modified)
> @@ -521,8 +521,7 @@
>          char       *p;
>          int            i;
>  
> -        val = (bytea *)
> -            DatumGetPointer(fastgetattr(ht_trig,
> +        val = DatumGetByteaP(fastgetattr(ht_trig,
>                                          Anum_pg_trigger_tgargs,
>                                          tgrel->rd_att, &isnull));
>          if (isnull)

> 
> ---------------------------(end of broadcast)---------------------------
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--  Bruce Momjian   bruce@momjian.us EnterpriseDB    http://www.enterprisedb.com
 + If your life is a hard drive, Christ can be your backup. +