Add support for Case exprs to fix_indxqual_references,

so that Case works in WHERE join clauses.  Temporary patch --- this routine
is one of many that ought to be changed to use centralized expression-tree-
walking logic.

src/backend/optimizer/plan/createplan.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.64 1999/07/27 03:51:03 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/optimizer/plan/createplan.c,v 1.65 1999/07/29 02:48:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -740,6 +740,37 @@ fix_indxqual_references(Node *clause, Path *index_path)
 
 		return (Node *) newnode;
 	}
+	else if (IsA(clause, CaseExpr))
+	{
+		CaseExpr   *oldnode = (CaseExpr *) clause;
+		CaseExpr   *newnode = makeNode(CaseExpr);
+
+		newnode->casetype = oldnode->casetype;
+		newnode->arg = oldnode->arg;	/* XXX should always be null
+										 * anyway ... */
+		newnode->args = (List *)
+			fix_indxqual_references((Node *) oldnode->args,
+									index_path);
+		newnode->defresult =
+			fix_indxqual_references(oldnode->defresult,
+									index_path);
+
+		return (Node *) newnode;
+	}
+	else if (IsA(clause, CaseWhen))
+	{
+		CaseWhen   *oldnode = (CaseWhen *) clause;
+		CaseWhen   *newnode = makeNode(CaseWhen);
+
+		newnode->expr =
+			fix_indxqual_references(oldnode->expr,
+									index_path);
+		newnode->result =
+			fix_indxqual_references(oldnode->result,
+									index_path);
+
+		return (Node *) newnode;
+	}
 	else
 	{
 		elog(ERROR, "fix_indxqual_references: Cannot handle node type %d",