Fix PREPARE TRANSACTION to reject the case where the transaction has dropped a

temporary table; we can't support that because there's no way to clean up the
source backend's internal state if the eventual COMMIT PREPARED is done by
another backend.  This was checked correctly in 8.1 but I broke it in 8.2 :-(.
Patch by Heikki Linnakangas, original trouble report by John Smith.

2 files changed, 2 insertions, 48 deletions

diff --git a/src/backend/storage/lmgr/lmgr.c b/src/backend/storage/lmgr/lmgr.c
index 4a4c0990ad2..25cd40cd1bd 100644
--- a/src/backend/storage/lmgr/lmgr.c
+++ b/src/backend/storage/lmgr/lmgr.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/lmgr.c,v 1.89 2006/10/04 00:29:57 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/lmgr.c,v 1.89.2.1 2008/03/04 19:54:23 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -19,12 +19,10 @@
 #include "access/transam.h"
 #include "access/xact.h"
 #include "catalog/catalog.h"
-#include "catalog/namespace.h"
 #include "miscadmin.h"
 #include "storage/lmgr.h"
 #include "storage/procarray.h"
 #include "utils/inval.h"
-#include "utils/lsyscache.h"
 
 
 /*
@@ -598,40 +596,3 @@ UnlockSharedObject(Oid classid, Oid objid, uint16 objsubid,
 
 	LockRelease(&tag, lockmode, false);
 }
-
-
-/*
- * LockTagIsTemp
- *		Determine whether a locktag is for a lock on a temporary object
- *
- * We need this because 2PC cannot deal with temp objects
- */
-bool
-LockTagIsTemp(const LOCKTAG *tag)
-{
-	switch (tag->locktag_type)
-	{
-		case LOCKTAG_RELATION:
-		case LOCKTAG_RELATION_EXTEND:
-		case LOCKTAG_PAGE:
-		case LOCKTAG_TUPLE:
-			/* check for lock on a temp relation */
-			/* field1 is dboid, field2 is reloid for all of these */
-			if ((Oid) tag->locktag_field1 == InvalidOid)
-				return false;	/* shared, so not temp */
-			if (isTempNamespace(get_rel_namespace((Oid) tag->locktag_field2)))
-				return true;
-			break;
-		case LOCKTAG_TRANSACTION:
-			/* there are no temp transactions */
-			break;
-		case LOCKTAG_OBJECT:
-			/* there are currently no non-table temp objects */
-			break;
-		case LOCKTAG_USERLOCK:
-		case LOCKTAG_ADVISORY:
-			/* assume these aren't temp */
-			break;
-	}
-	return false;				/* default case */
-}
diff --git a/src/backend/storage/lmgr/lock.c b/src/backend/storage/lmgr/lock.c
index a8d2ad01d9f..a49002e4d07 100644
--- a/src/backend/storage/lmgr/lock.c
+++ b/src/backend/storage/lmgr/lock.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.174.2.1 2008/02/02 22:26:23 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/lmgr/lock.c,v 1.174.2.2 2008/03/04 19:54:23 tgl Exp $
  *
  * NOTES
  *	  A lock table is a shared memory hash table.  When
@@ -37,7 +37,6 @@
 #include "access/twophase_rmgr.h"
 #include "miscadmin.h"
 #include "pgstat.h"
-#include "storage/lmgr.h"
 #include "utils/memutils.h"
 #include "utils/ps_status.h"
 #include "utils/resowner.h"
@@ -1849,12 +1848,6 @@ AtPrepare_Locks(void)
 				elog(ERROR, "cannot PREPARE when session locks exist");
 		}
 
-		/* Can't handle it if the lock is on a temporary object */
-		if (LockTagIsTemp(&locallock->tag.lock))
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("cannot PREPARE a transaction that has operated on temporary tables")));
-
 		/*
 		 * Create a 2PC record.
 		 */