Code review for domain-constraints patch. Use a new ConstraintTest node

type for runtime constraint checks, instead of misusing the parse-time
Constraint node for the purpose.  Fix some damage introduced into type
coercion logic; in particular ensure that a coerced expression tree will
read out the correct result type when inspected (patch had broken some
RelabelType cases).  Enforce domain NOT NULL constraints against columns
that are omitted from an INSERT.

2 files changed, 23 insertions, 18 deletions

diff --git a/src/backend/optimizer/prep/preptlist.c b/src/backend/optimizer/prep/preptlist.c
index b7c0bac12c8..41f9b2f9478 100644
--- a/src/backend/optimizer/prep/preptlist.c
+++ b/src/backend/optimizer/prep/preptlist.c
@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.54 2002/08/02 18:15:06 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/prep/preptlist.c,v 1.55 2002/08/31 22:10:43 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -27,6 +27,7 @@
 #include "nodes/makefuncs.h"
 #include "optimizer/prep.h"
 #include "parser/parsetree.h"
+#include "parser/parse_coerce.h"
 
 
 static List *expand_targetlist(List *tlist, int command_type,
@@ -162,6 +163,8 @@ expand_targetlist(List *tlist, int command_type,
 			 *
 			 * For INSERT, generate a NULL constant.  (We assume the
 			 * rewriter would have inserted any available default value.)
+			 * Also, if the column isn't dropped, apply any domain constraints
+			 * that might exist --- this is to catch domain NOT NULL.
 			 *
 			 * For UPDATE, generate a Var reference to the existing value of
 			 * the attribute, so that it gets copied to the new tuple.
@@ -182,6 +185,9 @@ expand_targetlist(List *tlist, int command_type,
 												  att_tup->attbyval,
 												  false,	/* not a set */
 												  false);
+					if (!att_tup->attisdropped)
+						new_expr = coerce_type_constraints(NULL, new_expr,
+														   atttype, false);
 					break;
 				case CMD_UPDATE:
 					/* Insert NULLs for dropped columns */
diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 9e8372139ef..3b5e6988396 100644
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.106 2002/07/20 05:16:58 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/util/clauses.c,v 1.107 2002/08/31 22:10:43 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -1882,12 +1882,14 @@ expression_tree_walker(Node *node,
 					return true;
 			}
 			break;
-		case T_Constraint:
-			return walker(((Constraint *) node)->raw_expr, context);
 		case T_NullTest:
 			return walker(((NullTest *) node)->arg, context);
 		case T_BooleanTest:
 			return walker(((BooleanTest *) node)->arg, context);
+		case T_ConstraintTest:
+			if (walker(((ConstraintTest *) node)->arg, context))
+				return true;
+			return walker(((ConstraintTest *) node)->check_expr, context);
 		case T_SubLink:
 			{
 				SubLink    *sublink = (SubLink *) node;
@@ -2238,20 +2240,6 @@ expression_tree_mutator(Node *node,
 				return (Node *) newnode;
 			}
 			break;
-		case T_Constraint:
-			{
-				/*
-				 * Used for confirming domains.  Only needed fields
-				 * within the executor are the name, raw expression
-				 * and constraint type.
-				 */
-				Constraint *con = (Constraint *) node;
-				Constraint *newnode;
-
-				FLATCOPY(newnode, con, Constraint);
-				MUTATE(newnode->raw_expr, con->raw_expr, Node *);
-				return (Node *) newnode;
-			}
 		case T_NullTest:
 			{
 				NullTest   *ntest = (NullTest *) node;
@@ -2272,6 +2260,17 @@ expression_tree_mutator(Node *node,
 				return (Node *) newnode;
 			}
 			break;
+		case T_ConstraintTest:
+			{
+				ConstraintTest *ctest = (ConstraintTest *) node;
+				ConstraintTest *newnode;
+
+				FLATCOPY(newnode, ctest, ConstraintTest);
+				MUTATE(newnode->arg, ctest->arg, Node *);
+				MUTATE(newnode->check_expr, ctest->check_expr, Node *);
+				return (Node *) newnode;
+			}
+			break;
 		case T_SubLink:
 			{
 				/*