Repair breakage of rules containing INSERT ... SELECT actions, per bug

report from Joel Burton.  Turns out that my simple idea of turning the
SELECT into a subquery does not interact well *at all* with the way the
rule rewriter works.  Really what we need to make INSERT ... SELECT work
cleanly is to decouple targetlists from rangetables: an INSERT ... SELECT
wants to have two levels of targetlist but only one rangetable.  No time
for that for 7.1, however, so I've inserted some ugly hacks to make the
rewriter know explicitly about the structure of INSERT ... SELECT queries.
Ugh :-(

1 files changed, 7 insertions, 5 deletions

diff --git a/src/backend/rewrite/rewriteDefine.c b/src/backend/rewrite/rewriteDefine.c
index a83e0202335..4eb7d7e89d2 100644
--- a/src/backend/rewrite/rewriteDefine.c
+++ b/src/backend/rewrite/rewriteDefine.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.55 2000/10/26 21:36:50 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/rewrite/rewriteDefine.c,v 1.56 2000/12/05 19:15:09 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -24,6 +24,7 @@
 #include "optimizer/clauses.h"
 #include "parser/parse_relation.h"
 #include "rewrite/rewriteDefine.h"
+#include "rewrite/rewriteManip.h"
 #include "rewrite/rewriteSupport.h"
 #include "storage/smgr.h"
 #include "utils/builtins.h"
@@ -205,16 +206,17 @@ DefineQueryRewrite(RuleStmt *stmt)
 	foreach(l, action)
 	{
 		query = (Query *) lfirst(l);
+		if (query->resultRelation == 0)
+			continue;
+		/* Don't be fooled by INSERT/SELECT */
+		if (query != getInsertSelectQuery(query, NULL))
+			continue;
 		if (query->resultRelation == PRS2_OLD_VARNO)
-		{
 			elog(ERROR, "rule actions on OLD currently not supported"
 				 "\n\tuse views or triggers instead");
-		}
 		if (query->resultRelation == PRS2_NEW_VARNO)
-		{
 			elog(ERROR, "rule actions on NEW currently not supported"
 				 "\n\tuse triggers instead");
-		}
 	}
 
 	/*