Somebody seems to have thought they could get away without checking for

rsinfo->expectedDesc == NULL in deflist_to_tuplestore(), but that doesn't
look very safe to me.  Noted in passing while studying problem report
from Greg Davidson.

diff --git a/src/backend/foreign/foreign.c b/src/backend/foreign/foreign.c
index 4fb00328ca1711f882065ac86d9c272de8b17170..04f0d348fb44712cb39af2d2e3c1f8b790e30f47 100644 (file)
--- a/src/backend/foreign/foreign.c
+++ b/src/backend/foreign/foreign.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/foreign/foreign.c,v 1.4 2009/06/11 14:48:57 momjian Exp $
+ *       $PostgreSQL: pgsql/src/backend/foreign/foreign.c,v 1.5 2009/06/11 16:14:18 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -279,7 +279,8 @@ deflist_to_tuplestore(ReturnSetInfo *rsinfo, List *options)
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("set-valued function called in context that cannot accept a set")));
-   if (!(rsinfo->allowedModes & SFRM_Materialize))
+   if (!(rsinfo->allowedModes & SFRM_Materialize) ||
+       rsinfo->expectedDesc == NULL)
        ereport(ERROR,
                (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
                 errmsg("materialize mode required, but it is not allowed in this context")));