*** pgsql/contrib/dblink/dblink.c	2008/01/14 02:49:47	1.69
--- pgsql/contrib/dblink/dblink.c	2008/11/30 23:24:01	1.69.2.1
***************
*** 8,14 ****
   * Darko Prenosil <Darko.Prenosil@finteh.hr>
   * Shridhar Daithankar <shridhar_daithankar@persistent.co.in>
   *
!  * $PostgreSQL: pgsql/contrib/dblink/dblink.c,v 1.68 2008/01/03 21:27:59 tgl Exp $
   * Copyright (c) 2001-2008, PostgreSQL Global Development Group
   * ALL RIGHTS RESERVED;
   *
--- 8,14 ----
   * Darko Prenosil <Darko.Prenosil@finteh.hr>
   * Shridhar Daithankar <shridhar_daithankar@persistent.co.in>
   *
!  * $PostgreSQL: pgsql/contrib/dblink/dblink.c,v 1.69 2008/01/14 02:49:47 tgl Exp $
   * Copyright (c) 2001-2008, PostgreSQL Global Development Group
   * ALL RIGHTS RESERVED;
   *
*************** dblink_connect(PG_FUNCTION_ARGS)
*** 226,232 ****
  	char	   *connstr = NULL;
  	char	   *connname = NULL;
  	char	   *msg;
- 	MemoryContext oldcontext;
  	PGconn	   *conn = NULL;
  	remoteConn *rconn = NULL;
  
--- 226,231 ----
*************** dblink_connect(PG_FUNCTION_ARGS)
*** 240,252 ****
  	else if (PG_NARGS() == 1)
  		connstr = GET_STR(PG_GETARG_TEXT_P(0));
  
- 	oldcontext = MemoryContextSwitchTo(TopMemoryContext);
- 
  	if (connname)
! 		rconn = (remoteConn *) palloc(sizeof(remoteConn));
! 	conn = PQconnectdb(connstr);
  
! 	MemoryContextSwitchTo(oldcontext);
  
  	if (PQstatus(conn) == CONNECTION_BAD)
  	{
--- 239,249 ----
  	else if (PG_NARGS() == 1)
  		connstr = GET_STR(PG_GETARG_TEXT_P(0));
  
  	if (connname)
! 		rconn = (remoteConn *) MemoryContextAlloc(TopMemoryContext,
! 												  sizeof(remoteConn));
  
! 	conn = PQconnectdb(connstr);
  
  	if (PQstatus(conn) == CONNECTION_BAD)
  	{
*************** dblink_fetch(PG_FUNCTION_ARGS)
*** 583,592 ****
  		funcctx = SRF_FIRSTCALL_INIT();
  
  		/*
! 		 * switch to memory context appropriate for multiple function calls
  		 */
- 		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
- 
  		res = PQexec(conn, buf.data);
  		if (!res ||
  			(PQresultStatus(res) != PGRES_COMMAND_OK &&
--- 580,589 ----
  		funcctx = SRF_FIRSTCALL_INIT();
  
  		/*
! 		 * Try to execute the query.  Note that since libpq uses malloc,
! 		 * the PGresult will be long-lived even though we are still in
! 		 * a short-lived memory context.
  		 */
  		res = PQexec(conn, buf.data);
  		if (!res ||
  			(PQresultStatus(res) != PGRES_COMMAND_OK &&
*************** dblink_fetch(PG_FUNCTION_ARGS)
*** 633,641 ****
  				break;
  		}
  
- 		/* make sure we have a persistent copy of the tupdesc */
- 		tupdesc = CreateTupleDescCopy(tupdesc);
- 
  		/* check result and tuple descriptor have the same number of columns */
  		if (PQnfields(res) != tupdesc->natts)
  			ereport(ERROR,
--- 630,635 ----
*************** dblink_fetch(PG_FUNCTION_ARGS)
*** 643,656 ****
  					 errmsg("remote query result rowtype does not match "
  							"the specified FROM clause rowtype")));
  
! 		/* fast track when no results */
  		if (funcctx->max_calls < 1)
  		{
! 			if (res)
! 				PQclear(res);
  			SRF_RETURN_DONE(funcctx);
  		}
  
  		/* store needed metadata for subsequent calls */
  		attinmeta = TupleDescGetAttInMetadata(tupdesc);
  		funcctx->attinmeta = attinmeta;
--- 637,661 ----
  					 errmsg("remote query result rowtype does not match "
  							"the specified FROM clause rowtype")));
  
! 		/*
! 		 * fast track when no results.  We could exit earlier, but then
! 		 * we'd not report error if the result tuple type is wrong.
! 		 */
  		if (funcctx->max_calls < 1)
  		{
! 			PQclear(res);
  			SRF_RETURN_DONE(funcctx);
  		}
  
+ 		/*
+ 		 * switch to memory context appropriate for multiple function calls,
+ 		 * so we can make long-lived copy of tupdesc etc
+ 		 */
+ 		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+ 
+ 		/* make sure we have a persistent copy of the tupdesc */
+ 		tupdesc = CreateTupleDescCopy(tupdesc);
+ 
  		/* store needed metadata for subsequent calls */
  		attinmeta = TupleDescGetAttInMetadata(tupdesc);
  		funcctx->attinmeta = attinmeta;
*************** dblink_record_internal(FunctionCallInfo
*** 841,847 ****
--- 846,855 ----
  				res = PQgetResult(conn);
  				/* NULL means we're all done with the async results */
  				if (!res)
+ 				{
+ 					MemoryContextSwitchTo(oldcontext);
  					SRF_RETURN_DONE(funcctx);
+ 				}
  			}
  
  			if (!res ||
*************** dblink_record_internal(FunctionCallInfo
*** 855,860 ****
--- 863,869 ----
  					DBLINK_RES_ERROR_AS_NOTICE("sql error");
  					if (freeconn)
  						PQfinish(conn);
+ 					MemoryContextSwitchTo(oldcontext);
  					SRF_RETURN_DONE(funcctx);
  				}
  			}
*************** dblink_record_internal(FunctionCallInfo
*** 925,930 ****
--- 934,940 ----
  			{
  				if (res)
  					PQclear(res);
+ 				MemoryContextSwitchTo(oldcontext);
  				SRF_RETURN_DONE(funcctx);
  			}
  
*************** dblink_get_pkey(PG_FUNCTION_ARGS)
*** 1296,1303 ****
--- 1306,1316 ----
  			funcctx->user_fctx = results;
  		}
  		else
+ 		{
  			/* fast track when no results */
+ 			MemoryContextSwitchTo(oldcontext);
  			SRF_RETURN_DONE(funcctx);
+ 		}
  
  		MemoryContextSwitchTo(oldcontext);
  	}