Index: backend/executor/nodeHash.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/backend/executor/nodeHash.c,v
retrieving revision 1.86
diff -c -r1.86 nodeHash.c
*** backend/executor/nodeHash.c	29 Aug 2004 04:12:31 -0000	1.86
--- backend/executor/nodeHash.c	22 Sep 2004 17:51:53 -0000
***************
*** 232,237 ****
--- 232,238 ----
  	hashtable->buckets = NULL;
  	hashtable->nbatch = nbatch;
  	hashtable->curbatch = 0;
+ 	hashtable->ntup = 0;
  	hashtable->innerBatchFile = NULL;
  	hashtable->outerBatchFile = NULL;
  	hashtable->innerBatchSize = NULL;
***************
*** 493,498 ****
--- 494,501 ----
  			   heapTuple->t_len);
  		hashTuple->next = hashtable->buckets[bucketno];
  		hashtable->buckets[bucketno] = hashTuple;
+ 
+ 		hashtable->ntup ++;
  	}
  	else
  	{
Index: backend/executor/nodeHashjoin.c
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/backend/executor/nodeHashjoin.c,v
retrieving revision 1.64
diff -c -r1.64 nodeHashjoin.c
*** backend/executor/nodeHashjoin.c	29 Aug 2004 05:06:42 -0000	1.64
--- backend/executor/nodeHashjoin.c	22 Sep 2004 17:51:54 -0000
***************
*** 127,132 ****
--- 127,140 ----
  		hashNode->hashtable = hashtable;
  		(void) ExecProcNode((PlanState *) hashNode);
  
+ 		/* An empty hash table can't return any matches */
+ 		if (hashtable->nbatch == 0 && 
+ 			hashtable->ntup == 0 &&
+ 			node->js.jointype != JOIN_LEFT) 
+ 		{
+ 			return NULL;
+ 		}
+ 		
  		/*
  		 * Open temp files for outer batches, if needed. Note that file
  		 * buffers are palloc'd in regular executor context.
Index: include/executor/hashjoin.h
===================================================================
RCS file: /projects/cvsroot/pgsql-server/src/include/executor/hashjoin.h,v
retrieving revision 1.32
diff -c -r1.32 hashjoin.h
*** include/executor/hashjoin.h	29 Aug 2004 04:13:06 -0000	1.32
--- include/executor/hashjoin.h	22 Sep 2004 17:52:04 -0000
***************
*** 57,62 ****
--- 57,64 ----
  	int			nbatch;			/* number of batches; 0 means 1-pass join */
  	int			curbatch;		/* current batch #, or 0 during 1st pass */
  
+ 	int			ntup;			/* Total number of tuples hashed in this batch */
+ 
  	/*
  	 * all these arrays are allocated for the life of the hash join, but
  	 * only if nbatch > 0: