Don't choke when exec_move_row assigns a synthesized null to a column

that happens to be composite itself.  Per bug #5314 from Oleg Serov.

Backpatch to 8.0 --- 7.4 has got too many other shortcomings in
composite-type support to make this worth worrying about in that branch.

diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 1b400341af4ee895a17c0efeb674fafd408e220c..3064c906bd5d844f9331384a7fee49e3380957fc 100644 (file)
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -3,7 +3,7 @@
  *           procedural language
  *
  * IDENTIFICATION
- *   $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.154.2.9 2009/12/29 17:41:35 heikki Exp $
+ *   $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.154.2.10 2010/02/12 19:38:08 tgl Exp $
  *
  *   This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -3104,12 +3104,6 @@ exec_assign_value(PLpgSQL_execstate *estate,
                 */
                PLpgSQL_row *row = (PLpgSQL_row *) target;
 
-               /* Source must be of RECORD or composite type */
-               if (!(valtype == RECORDOID ||
-                     get_typtype(valtype) == 'c'))
-                   ereport(ERROR,
-                           (errcode(ERRCODE_DATATYPE_MISMATCH),
-                            errmsg("cannot assign non-composite value to a row variable")));
                if (*isNull)
                {
                    /* If source is null, just assign nulls to the row */
@@ -3123,7 +3117,13 @@ exec_assign_value(PLpgSQL_execstate *estate,
                    TupleDesc   tupdesc;
                    HeapTupleData tmptup;
 
-                   /* Else source is a tuple Datum, safe to do this: */
+                   /* Source must be of RECORD or composite type */
+                   if (!(valtype == RECORDOID ||
+                         get_typtype(valtype) == 'c'))
+                       ereport(ERROR,
+                               (errcode(ERRCODE_DATATYPE_MISMATCH),
+                                errmsg("cannot assign non-composite value to a row variable")));
+                   /* So source is a tuple Datum, safe to do this: */
                    td = DatumGetHeapTupleHeader(value);
                    /* Extract rowtype info and find a tupdesc */
                    tupType = HeapTupleHeaderGetTypeId(td);
@@ -3148,12 +3148,6 @@ exec_assign_value(PLpgSQL_execstate *estate,
                 */
                PLpgSQL_rec *rec = (PLpgSQL_rec *) target;
 
-               /* Source must be of RECORD or composite type */
-               if (!(valtype == RECORDOID ||
-                     get_typtype(valtype) == 'c'))
-                   ereport(ERROR,
-                           (errcode(ERRCODE_DATATYPE_MISMATCH),
-                            errmsg("cannot assign non-composite value to a record variable")));
                if (*isNull)
                {
                    /* If source is null, just assign nulls to the record */
@@ -3167,7 +3161,13 @@ exec_assign_value(PLpgSQL_execstate *estate,
                    TupleDesc   tupdesc;
                    HeapTupleData tmptup;
 
-                   /* Else source is a tuple Datum, safe to do this: */
+                   /* Source must be of RECORD or composite type */
+                   if (!(valtype == RECORDOID ||
+                         get_typtype(valtype) == 'c'))
+                       ereport(ERROR,
+                               (errcode(ERRCODE_DATATYPE_MISMATCH),
+                                errmsg("cannot assign non-composite value to a record variable")));
+                   /* So source is a tuple Datum, safe to do this: */
                    td = DatumGetHeapTupleHeader(value);
                    /* Extract rowtype info and find a tupdesc */
                    tupType = HeapTupleHeaderGetTypeId(td);