From 2deef968f4dac488549d1e0b827e4abb2c524363 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sun, 18 Apr 1999 17:35:51 +0000
Subject: [PATCH] After transforming a CASE expr with a default argument,
delete the default argument from the node. This prevents the executor from
spitting up on the untransformed argument expression. Typical failure was:
select (case f1 when 'val' then 'subst' else f1 end) from t1; ERROR:
copyObject: don't know how to copy 704
---
src/backend/parser/parse_expr.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/src/backend/parser/parse_expr.c b/src/backend/parser/parse_expr.c
index 6de507bae04..d23d7214a34 100644
--- a/src/backend/parser/parse_expr.c
+++ b/src/backend/parser/parse_expr.c
@@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
- * $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.40 1999/02/03 21:16:57 momjian Exp $
+ * $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.41 1999/04/18 17:35:51 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -345,9 +345,9 @@ transformExpr(ParseState *pstate, Node *expr, int precedence)
foreach(args, c->args)
{
w = lfirst(args);
- /* shorthand form was specified, so expand... */
if (c->arg != NULL)
{
+ /* shorthand form was specified, so expand... */
A_Expr *a = makeNode(A_Expr);
a->oper = OP;
a->opname = "=";
@@ -358,6 +358,13 @@ transformExpr(ParseState *pstate, Node *expr, int precedence)
lfirst(args) = transformExpr(pstate, (Node *) w, precedence);
}
+ /* It's not shorthand anymore, so drop the implicit argument.
+ * This is necessary to keep the executor from seeing an
+ * untransformed expression...
+ */
+ c->arg = NULL;
+
+ /* transform the default clause */
if (c->defresult == NULL)
{
A_Const *n = makeNode(A_Const);
@@ -365,9 +372,9 @@ transformExpr(ParseState *pstate, Node *expr, int precedence)
c->defresult = (Node *)n;
}
c->defresult = transformExpr(pstate, (Node *) c->defresult, precedence);
- c->casetype = exprType(c->defresult);
/* now check types across result clauses... */
+ c->casetype = exprType(c->defresult);
ptype = c->casetype;
pcategory = TypeCategory(ptype);
foreach(args, c->args)
--
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