Index: src/backend/access/gist/gistget.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/access/gist/gistget.c,v
retrieving revision 1.55
diff -c -r1.55 gistget.c
*** src/backend/access/gist/gistget.c	14 Jan 2006 22:03:35 -0000	1.55
--- src/backend/access/gist/gistget.c	20 Feb 2006 00:41:03 -0000
***************
*** 96,102 ****
  gistgettuple(PG_FUNCTION_ARGS)
  {
  	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
! 	ScanDirection dir = (ScanDirection) PG_GETARG_INT32(1);
  	GISTScanOpaque so;
  	ItemPointerData tid;
  	bool		res;
--- 96,102 ----
  gistgettuple(PG_FUNCTION_ARGS)
  {
  	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
! 	ScanDirection dir = (ScanDirection) PG_GETARG_CHAR(1);
  	GISTScanOpaque so;
  	ItemPointerData tid;
  	bool		res;
Index: src/backend/access/hash/hash.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/access/hash/hash.c,v
retrieving revision 1.86
diff -c -r1.86 hash.c
*** src/backend/access/hash/hash.c	11 Feb 2006 23:31:33 -0000	1.86
--- src/backend/access/hash/hash.c	20 Feb 2006 00:41:04 -0000
***************
*** 164,170 ****
  hashgettuple(PG_FUNCTION_ARGS)
  {
  	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
! 	ScanDirection dir = (ScanDirection) PG_GETARG_INT32(1);
  	HashScanOpaque so = (HashScanOpaque) scan->opaque;
  	Relation	rel = scan->indexRelation;
  	Page		page;
--- 164,170 ----
  hashgettuple(PG_FUNCTION_ARGS)
  {
  	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
! 	ScanDirection dir = (ScanDirection) PG_GETARG_CHAR(1);
  	HashScanOpaque so = (HashScanOpaque) scan->opaque;
  	Relation	rel = scan->indexRelation;
  	Page		page;
Index: src/backend/access/heap/heapam.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/access/heap/heapam.c,v
retrieving revision 1.206
diff -c -r1.206 heapam.c
*** src/backend/access/heap/heapam.c	11 Jan 2006 08:43:11 -0000	1.206
--- src/backend/access/heap/heapam.c	20 Feb 2006 00:41:05 -0000
***************
*** 172,178 ****
   *		tuple as indicated by "dir"; return the next tuple in scan->rs_ctup,
   *		or set scan->rs_ctup.t_data = NULL if no more tuples.
   *
!  * dir == 0 means "re-fetch the tuple indicated by scan->rs_ctup".
   *
   * Note: the reason nkeys/key are passed separately, even though they are
   * kept in the scan descriptor, is that the caller may not want us to check
--- 172,179 ----
   *		tuple as indicated by "dir"; return the next tuple in scan->rs_ctup,
   *		or set scan->rs_ctup.t_data = NULL if no more tuples.
   *
!  * dir == NoMovementScanDirection means "re-fetch the tuple indicated by
!  * scan->rs_ctup".
   *
   * Note: the reason nkeys/key are passed separately, even though they are
   * kept in the scan descriptor, is that the caller may not want us to check
***************
*** 189,200 ****
   */
  static void
  heapgettup(HeapScanDesc scan,
! 		   int dir,
  		   int nkeys,
  		   ScanKey key)
  {
  	HeapTuple	tuple = &(scan->rs_ctup);
  	Snapshot	snapshot = scan->rs_snapshot;
  	BlockNumber page;
  	Page		dp;
  	int			lines;
--- 190,202 ----
   */
  static void
  heapgettup(HeapScanDesc scan,
! 		   ScanDirection dir,
  		   int nkeys,
  		   ScanKey key)
  {
  	HeapTuple	tuple = &(scan->rs_ctup);
  	Snapshot	snapshot = scan->rs_snapshot;
+ 	bool		backward = ScanDirectionIsBackward(dir);
  	BlockNumber page;
  	Page		dp;
  	int			lines;
***************
*** 205,211 ****
  	/*
  	 * calculate next starting lineoff, given scan direction
  	 */
! 	if (dir > 0)
  	{
  		/*
  		 * forward scan direction
--- 207,213 ----
  	/*
  	 * calculate next starting lineoff, given scan direction
  	 */
! 	if (ScanDirectionIsForward(dir))
  	{
  		/*
  		 * forward scan direction
***************
*** 242,248 ****
  
  		linesleft = lines - lineoff + 1;
  	}
! 	else if (dir < 0)
  	{
  		/*
  		 * reverse scan direction
--- 244,250 ----
  
  		linesleft = lines - lineoff + 1;
  	}
! 	else if (backward)
  	{
  		/*
  		 * reverse scan direction
***************
*** 352,358 ****
  			 * otherwise move to the next item on the page
  			 */
  			--linesleft;
! 			if (dir < 0)
  			{
  				--lpp;			/* move back in this page's ItemId array */
  				--lineoff;
--- 354,360 ----
  			 * otherwise move to the next item on the page
  			 */
  			--linesleft;
! 			if (backward)
  			{
  				--lpp;			/* move back in this page's ItemId array */
  				--lineoff;
***************
*** 373,379 ****
  		/*
  		 * return NULL if we've exhausted all the pages
  		 */
! 		if ((dir < 0) ? (page == 0) : (page + 1 >= scan->rs_nblocks))
  		{
  			if (BufferIsValid(scan->rs_cbuf))
  				ReleaseBuffer(scan->rs_cbuf);
--- 375,381 ----
  		/*
  		 * return NULL if we've exhausted all the pages
  		 */
! 		if ((backward) ? (page == 0) : (page + 1 >= scan->rs_nblocks))
  		{
  			if (BufferIsValid(scan->rs_cbuf))
  				ReleaseBuffer(scan->rs_cbuf);
***************
*** 384,390 ****
  			return;
  		}
  
! 		page = (dir < 0) ? (page - 1) : (page + 1);
  
  		heapgetpage(scan, page);
  
--- 386,392 ----
  			return;
  		}
  
! 		page = (backward) ? (page - 1) : (page + 1);
  
  		heapgetpage(scan, page);
  
***************
*** 393,399 ****
  		dp = (Page) BufferGetPage(scan->rs_cbuf);
  		lines = PageGetMaxOffsetNumber((Page) dp);
  		linesleft = lines;
! 		if (dir < 0)
  		{
  			lineoff = lines;
  			lpp = PageGetItemId(dp, lines);
--- 395,401 ----
  		dp = (Page) BufferGetPage(scan->rs_cbuf);
  		lines = PageGetMaxOffsetNumber((Page) dp);
  		linesleft = lines;
! 		if (backward)
  		{
  			lineoff = lines;
  			lpp = PageGetItemId(dp, lines);
***************
*** 421,431 ****
   */
  static void
  heapgettup_pagemode(HeapScanDesc scan,
! 					int dir,
  					int nkeys,
  					ScanKey key)
  {
  	HeapTuple	tuple = &(scan->rs_ctup);
  	BlockNumber page;
  	Page		dp;
  	int			lines;
--- 423,434 ----
   */
  static void
  heapgettup_pagemode(HeapScanDesc scan,
! 					ScanDirection dir,
  					int nkeys,
  					ScanKey key)
  {
  	HeapTuple	tuple = &(scan->rs_ctup);
+ 	bool		backward = ScanDirectionIsBackward(dir);
  	BlockNumber page;
  	Page		dp;
  	int			lines;
***************
*** 437,443 ****
  	/*
  	 * calculate next starting lineindex, given scan direction
  	 */
! 	if (dir > 0)
  	{
  		/*
  		 * forward scan direction
--- 440,446 ----
  	/*
  	 * calculate next starting lineindex, given scan direction
  	 */
! 	if (ScanDirectionIsForward(dir))
  	{
  		/*
  		 * forward scan direction
***************
*** 471,477 ****
  
  		linesleft = lines - lineindex;
  	}
! 	else if (dir < 0)
  	{
  		/*
  		 * reverse scan direction
--- 474,480 ----
  
  		linesleft = lines - lineindex;
  	}
! 	else if (backward)
  	{
  		/*
  		 * reverse scan direction
***************
*** 584,590 ****
  			 * otherwise move to the next item on the page
  			 */
  			--linesleft;
! 			if (dir < 0)
  			{
  				--lineindex;
  			}
--- 587,593 ----
  			 * otherwise move to the next item on the page
  			 */
  			--linesleft;
! 			if (backward)
  			{
  				--lineindex;
  			}
***************
*** 602,608 ****
  		/*
  		 * return NULL if we've exhausted all the pages
  		 */
! 		if ((dir < 0) ? (page == 0) : (page + 1 >= scan->rs_nblocks))
  		{
  			if (BufferIsValid(scan->rs_cbuf))
  				ReleaseBuffer(scan->rs_cbuf);
--- 605,611 ----
  		/*
  		 * return NULL if we've exhausted all the pages
  		 */
! 		if ((backward) ? (page == 0) : (page + 1 >= scan->rs_nblocks))
  		{
  			if (BufferIsValid(scan->rs_cbuf))
  				ReleaseBuffer(scan->rs_cbuf);
***************
*** 613,626 ****
  			return;
  		}
  
! 		page = (dir < 0) ? (page - 1) : (page + 1);
  
  		heapgetpage(scan, page);
  
  		dp = (Page) BufferGetPage(scan->rs_cbuf);
  		lines = scan->rs_ntuples;
  		linesleft = lines;
! 		if (dir < 0)
  			lineindex = lines - 1;
  		else
  			lineindex = 0;
--- 616,629 ----
  			return;
  		}
  
! 		page = (backward) ? (page - 1) : (page + 1);
  
  		heapgetpage(scan, page);
  
  		dp = (Page) BufferGetPage(scan->rs_cbuf);
  		lines = scan->rs_ntuples;
  		linesleft = lines;
! 		if (backward)
  			lineindex = lines - 1;
  		else
  			lineindex = 0;
***************
*** 988,995 ****
  
  #ifdef HEAPDEBUGALL
  #define HEAPDEBUG_1 \
! 	elog(DEBUG2, "heap_getnext([%s,nkeys=%d],dir=%d) called", \
! 		 RelationGetRelationName(scan->rs_rd), scan->rs_nkeys, (int) direction)
  #define HEAPDEBUG_2 \
  	elog(DEBUG2, "heap_getnext returning EOS")
  #define HEAPDEBUG_3 \
--- 991,998 ----
  
  #ifdef HEAPDEBUGALL
  #define HEAPDEBUG_1 \
! 	elog(DEBUG2, "heap_getnext([%s,nkeys=%d],dir=%c) called", \
! 		 RelationGetRelationName(scan->rs_rd), scan->rs_nkeys, direction)
  #define HEAPDEBUG_2 \
  	elog(DEBUG2, "heap_getnext returning EOS")
  #define HEAPDEBUG_3 \
***************
*** 1008,1022 ****
  
  	HEAPDEBUG_1;				/* heap_getnext( info ) */
  
- 	/*
- 	 * Note: we depend here on the -1/0/1 encoding of ScanDirection.
- 	 */
  	if (scan->rs_pageatatime)
! 		heapgettup_pagemode(scan, (int) direction,
! 							scan->rs_nkeys, scan->rs_key);
  	else
! 		heapgettup(scan, (int) direction,
! 				   scan->rs_nkeys, scan->rs_key);
  
  	if (scan->rs_ctup.t_data == NULL)
  	{
--- 1011,1020 ----
  
  	HEAPDEBUG_1;				/* heap_getnext( info ) */
  
  	if (scan->rs_pageatatime)
! 		heapgettup_pagemode(scan, direction, scan->rs_nkeys, scan->rs_key);
  	else
! 		heapgettup(scan, direction, scan->rs_nkeys, scan->rs_key);
  
  	if (scan->rs_ctup.t_data == NULL)
  	{
***************
*** 2745,2757 ****
  		{
  			scan->rs_cindex = scan->rs_mindex;
  			heapgettup_pagemode(scan,
! 								0,			/* "no movement" */
  								0,			/* needn't recheck scan keys */
  								NULL);
  		}
  		else
  			heapgettup(scan,
! 					   0,					/* "no movement" */
  					   0,					/* needn't recheck scan keys */
  					   NULL);
  	}
--- 2743,2755 ----
  		{
  			scan->rs_cindex = scan->rs_mindex;
  			heapgettup_pagemode(scan,
! 								NoMovementScanDirection,			/* "no movement" */
  								0,			/* needn't recheck scan keys */
  								NULL);
  		}
  		else
  			heapgettup(scan,
! 					   NoMovementScanDirection,					/* "no movement" */
  					   0,					/* needn't recheck scan keys */
  					   NULL);
  	}
Index: src/backend/access/nbtree/nbtree.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/access/nbtree/nbtree.c,v
retrieving revision 1.141
diff -c -r1.141 nbtree.c
*** src/backend/access/nbtree/nbtree.c	14 Feb 2006 17:20:01 -0000	1.141
--- src/backend/access/nbtree/nbtree.c	20 Feb 2006 00:41:06 -0000
***************
*** 233,239 ****
  btgettuple(PG_FUNCTION_ARGS)
  {
  	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
! 	ScanDirection dir = (ScanDirection) PG_GETARG_INT32(1);
  	BTScanOpaque so = (BTScanOpaque) scan->opaque;
  	Page		page;
  	OffsetNumber offnum;
--- 233,239 ----
  btgettuple(PG_FUNCTION_ARGS)
  {
  	IndexScanDesc scan = (IndexScanDesc) PG_GETARG_POINTER(0);
! 	ScanDirection dir = (ScanDirection) PG_GETARG_CHAR(1);
  	BTScanOpaque so = (BTScanOpaque) scan->opaque;
  	Page		page;
  	OffsetNumber offnum;
Index: src/backend/executor/execMain.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/executor/execMain.c,v
retrieving revision 1.266
diff -c -r1.266 execMain.c
*** src/backend/executor/execMain.c	19 Feb 2006 00:04:26 -0000	1.266
--- src/backend/executor/execMain.c	20 Feb 2006 00:41:07 -0000
***************
*** 218,224 ****
  	/*
  	 * run plan
  	 */
! 	if (direction == NoMovementScanDirection)
  		result = NULL;
  	else
  		result = ExecutePlan(estate,
--- 218,224 ----
  	/*
  	 * run plan
  	 */
! 	if (ScanDirectionIsNoMovement(direction))
  		result = NULL;
  	else
  		result = ExecutePlan(estate,
Index: src/backend/nodes/outfuncs.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/nodes/outfuncs.c,v
retrieving revision 1.268
diff -c -r1.268 outfuncs.c
*** src/backend/nodes/outfuncs.c	19 Feb 2006 00:04:26 -0000	1.268
--- src/backend/nodes/outfuncs.c	20 Feb 2006 00:41:07 -0000
***************
*** 356,362 ****
  	WRITE_NODE_FIELD(indexqualorig);
  	WRITE_NODE_FIELD(indexstrategy);
  	WRITE_NODE_FIELD(indexsubtype);
! 	WRITE_ENUM_FIELD(indexorderdir, ScanDirection);
  }
  
  static void
--- 356,362 ----
  	WRITE_NODE_FIELD(indexqualorig);
  	WRITE_NODE_FIELD(indexstrategy);
  	WRITE_NODE_FIELD(indexsubtype);
! 	WRITE_CHAR_FIELD(indexorderdir);
  }
  
  static void
***************
*** 1041,1047 ****
  	WRITE_NODE_FIELD(indexclauses);
  	WRITE_NODE_FIELD(indexquals);
  	WRITE_BOOL_FIELD(isjoininner);
! 	WRITE_ENUM_FIELD(indexscandir, ScanDirection);
  	WRITE_FLOAT_FIELD(indextotalcost, "%.2f");
  	WRITE_FLOAT_FIELD(indexselectivity, "%.4f");
  	WRITE_FLOAT_FIELD(rows, "%.0f");
--- 1041,1047 ----
  	WRITE_NODE_FIELD(indexclauses);
  	WRITE_NODE_FIELD(indexquals);
  	WRITE_BOOL_FIELD(isjoininner);
! 	WRITE_CHAR_FIELD(indexscandir);
  	WRITE_FLOAT_FIELD(indextotalcost, "%.2f");
  	WRITE_FLOAT_FIELD(indexselectivity, "%.4f");
  	WRITE_FLOAT_FIELD(rows, "%.0f");
Index: src/backend/tcop/pquery.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/tcop/pquery.c,v
retrieving revision 1.98
diff -c -r1.98 pquery.c
*** src/backend/tcop/pquery.c	22 Nov 2005 18:17:21 -0000	1.98
--- src/backend/tcop/pquery.c	20 Feb 2006 00:41:08 -0000
***************
*** 795,801 ****
  			nprocessed = queryDesc->estate->es_processed;
  		}
  
! 		if (direction != NoMovementScanDirection)
  		{
  			long		oldPos;
  
--- 795,801 ----
  			nprocessed = queryDesc->estate->es_processed;
  		}
  
! 		if (!ScanDirectionIsNoMovement(direction))
  		{
  			long		oldPos;
  
***************
*** 837,843 ****
  			nprocessed = queryDesc->estate->es_processed;
  		}
  
! 		if (direction != NoMovementScanDirection)
  		{
  			if (nprocessed > 0 && portal->atEnd)
  			{
--- 837,843 ----
  			nprocessed = queryDesc->estate->es_processed;
  		}
  
! 		if (!ScanDirectionIsNoMovement(direction))
  		{
  			if (nprocessed > 0 && portal->atEnd)
  			{
***************
*** 890,902 ****
  
  	(*dest->rStartup) (dest, CMD_SELECT, portal->tupDesc);
  
! 	if (direction == NoMovementScanDirection)
  	{
  		/* do nothing except start/stop the destination */
  	}
  	else
  	{
! 		bool		forward = (direction == ForwardScanDirection);
  
  		for (;;)
  		{
--- 890,902 ----
  
  	(*dest->rStartup) (dest, CMD_SELECT, portal->tupDesc);
  
! 	if (ScanDirectionIsNoMovement(direction))
  	{
  		/* do nothing except start/stop the destination */
  	}
  	else
  	{
! 		bool		forward = (ScanDirectionIsForward(direction));
  
  		for (;;)
  		{
Index: src/include/access/sdir.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/access/sdir.h,v
retrieving revision 1.17
diff -c -r1.17 sdir.h
*** src/include/access/sdir.h	31 Dec 2004 22:03:21 -0000	1.17
--- src/include/access/sdir.h	20 Feb 2006 00:41:09 -0000
***************
*** 15,38 ****
  #define SDIR_H
  
  
! /*
!  * ScanDirection was an int8 for no apparent reason. I kept the original
!  * values because I'm not sure if I'll break anything otherwise.  -ay 2/95
!  */
! typedef enum ScanDirection
! {
! 	BackwardScanDirection = -1,
! 	NoMovementScanDirection = 0,
! 	ForwardScanDirection = 1
! } ScanDirection;
  
  /*
   * ScanDirectionIsValid
   *		True iff scan direction is valid.
   */
  #define ScanDirectionIsValid(direction) \
! 	((bool) (BackwardScanDirection <= (direction) && \
! 			 (direction) <= ForwardScanDirection))
  
  /*
   * ScanDirectionIsBackward
--- 15,33 ----
  #define SDIR_H
  
  
! typedef char ScanDirection;
! #define BackwardScanDirection	 ((ScanDirection) 'b')
! #define NoMovementScanDirection	 ((ScanDirection) 'n')
! #define ForwardScanDirection	 ((ScanDirection) 'f')
  
  /*
   * ScanDirectionIsValid
   *		True iff scan direction is valid.
   */
  #define ScanDirectionIsValid(direction) \
! 	((bool) (BackwardScanDirection == (direction) || \
! 			 NoMovementScanDirection == (direction) || \
! 			 ForwardScanDirection == (direction)))
  
  /*
   * ScanDirectionIsBackward