diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 193e80c1528..07791ffc86d 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.65.2.4 2005/06/20 20:45:06 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.65.2.5 2007/02/08 18:38:31 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -767,26 +767,26 @@ exec_stmt_block(PLpgSQL_execstate * estate, PLpgSQL_stmt_block * block)
 				{
 					PLpgSQL_var *var = (PLpgSQL_var *) (estate->datums[n]);
 
+					/* free any old value, in case re-entering block */
 					if (var->freeval)
 					{
 						pfree((void *) (var->value));
 						var->freeval = false;
 					}
 
-					if (!var->isconst || var->isnull)
+					/* Initially it contains a NULL */
+					var->value = (Datum) 0;
+					var->isnull = true;
+
+					if (var->default_val == NULL)
 					{
-						if (var->default_val == NULL)
-						{
-							var->value = (Datum) 0;
-							var->isnull = true;
-							if (var->notnull)
-								elog(ERROR, "variable '%s' declared NOT NULL cannot default to NULL", var->refname);
-						}
-						else
-						{
-							exec_assign_expr(estate, (PLpgSQL_datum *) var,
-											 var->default_val);
-						}
+						if (var->notnull)
+							elog(ERROR, "variable '%s' declared NOT NULL cannot default to NULL", var->refname);
+					}
+					else
+					{
+						exec_assign_expr(estate, (PLpgSQL_datum *) var,
+										 var->default_val);
 					}
 				}
 				break;