From 4f896dac17f7015b34347e278fc3db4047b86e43 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 22 Mar 2007 19:55:04 +0000
Subject: Arrange for PreventTransactionChain to reject commands submitted as
 part of a multi-statement simple-Query message.  This bug goes all the way
 back, but unfortunately is not nearly so easy to fix in existing releases; it
 is only the recent ProcessUtility API change that makes it fixable in HEAD. 
 Per report from William Garrison.

---
 src/backend/tcop/postgres.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

(limited to 'src/backend/tcop/postgres.c')

diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index f997d524101..9f55ba2e387 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.528 2007/03/13 00:33:42 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/tcop/postgres.c,v 1.529 2007/03/22 19:55:04 tgl Exp $
  *
  * NOTES
  *	  this is the "main" module of the postgres backend and
@@ -765,6 +765,7 @@ exec_simple_query(const char *query_string)
 	ListCell   *parsetree_item;
 	bool		save_log_statement_stats = log_statement_stats;
 	bool		was_logged = false;
+	bool		isTopLevel;
 	char		msec_str[32];
 
 	/*
@@ -824,6 +825,15 @@ exec_simple_query(const char *query_string)
 	 */
 	MemoryContextSwitchTo(oldcontext);
 
+	/*
+	 * We'll tell PortalRun it's a top-level command iff there's exactly
+	 * one raw parsetree.  If more than one, it's effectively a transaction
+	 * block and we want PreventTransactionChain to reject unsafe commands.
+	 * (Note: we're assuming that query rewrite cannot add commands that are
+	 * significant to PreventTransactionChain.)
+	 */
+	isTopLevel = (list_length(parsetree_list) == 1);
+
 	/*
 	 * Run through the raw parsetree(s) and process each one.
 	 */
@@ -944,7 +954,7 @@ exec_simple_query(const char *query_string)
 		 */
 		(void) PortalRun(portal,
 						 FETCH_ALL,
-						 true,	/* top level */
+						 isTopLevel,
 						 receiver,
 						 receiver,
 						 completionTag);
@@ -1810,7 +1820,7 @@ exec_execute_message(const char *portal_name, long max_rows)
 
 	completed = PortalRun(portal,
 						  max_rows,
-						  true,	/* top level */
+						  true,					/* always top level */
 						  receiver,
 						  receiver,
 						  completionTag);
-- 
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