Index: src/backend/access/transam/xlog.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/backend/access/transam/xlog.c,v
retrieving revision 1.264
diff -a -u -r1.264 xlog.c
--- src/backend/access/transam/xlog.c	14 Feb 2007 05:00:40 -0000	1.264
+++ src/backend/access/transam/xlog.c	23 Feb 2007 15:09:09 -0000
@@ -4039,7 +4039,6 @@
 	/* Set up information for the initial checkpoint record */
 	checkPoint.redo.xlogid = 0;
 	checkPoint.redo.xrecoff = SizeOfXLogLongPHD;
-	checkPoint.undo = checkPoint.redo;
 	checkPoint.ThisTimeLineID = ThisTimeLineID;
 	checkPoint.nextXidEpoch = 0;
 	checkPoint.nextXid = FirstNormalTransactionId;
@@ -4698,9 +4697,8 @@
 	wasShutdown = (record->xl_info == XLOG_CHECKPOINT_SHUTDOWN);
 
 	ereport(LOG,
-	 (errmsg("redo record is at %X/%X; undo record is at %X/%X; shutdown %s",
+	 (errmsg("redo record is at %X/%X; shutdown %s",
 			 checkPoint.redo.xlogid, checkPoint.redo.xrecoff,
-			 checkPoint.undo.xlogid, checkPoint.undo.xrecoff,
 			 wasShutdown ? "TRUE" : "FALSE")));
 	ereport(LOG,
 			(errmsg("next transaction ID: %u/%u; next OID: %u",
@@ -4730,20 +4728,17 @@
 	if (XLByteLT(RecPtr, checkPoint.redo))
 		ereport(PANIC,
 				(errmsg("invalid redo in checkpoint record")));
-	if (checkPoint.undo.xrecoff == 0)
-		checkPoint.undo = RecPtr;
 
 	/*
 	 * Check whether we need to force recovery from WAL.  If it appears to
 	 * have been a clean shutdown and we did not have a recovery.conf file,
 	 * then assume no recovery needed.
 	 */
-	if (XLByteLT(checkPoint.undo, RecPtr) ||
-		XLByteLT(checkPoint.redo, RecPtr))
+	if (XLByteLT(checkPoint.redo, RecPtr))
 	{
 		if (wasShutdown)
 			ereport(PANIC,
-				(errmsg("invalid redo/undo record in shutdown checkpoint")));
+				(errmsg("invalid redo record in shutdown checkpoint")));
 		InRecovery = true;
 	}
 	else if (ControlFile->state != DB_SHUTDOWNED)
@@ -5850,10 +5845,9 @@
 	{
 		CheckPoint *checkpoint = (CheckPoint *) rec;
 
-		appendStringInfo(buf, "checkpoint: redo %X/%X; undo %X/%X; "
+		appendStringInfo(buf, "checkpoint: redo %X/%X; "
 						 "tli %u; xid %u/%u; oid %u; multi %u; offset %u; %s",
 						 checkpoint->redo.xlogid, checkpoint->redo.xrecoff,
-						 checkpoint->undo.xlogid, checkpoint->undo.xrecoff,
 						 checkpoint->ThisTimeLineID,
 						 checkpoint->nextXidEpoch, checkpoint->nextXid,
 						 checkpoint->nextOid,
Index: src/bin/pg_controldata/pg_controldata.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/bin/pg_controldata/pg_controldata.c,v
retrieving revision 1.32
diff -a -u -r1.32 pg_controldata.c
--- src/bin/pg_controldata/pg_controldata.c	8 Dec 2006 19:50:53 -0000	1.32
+++ src/bin/pg_controldata/pg_controldata.c	23 Feb 2007 15:09:09 -0000
@@ -168,9 +168,6 @@
 	printf(_("Latest checkpoint's REDO location:    %X/%X\n"),
 		   ControlFile.checkPointCopy.redo.xlogid,
 		   ControlFile.checkPointCopy.redo.xrecoff);
-	printf(_("Latest checkpoint's UNDO location:    %X/%X\n"),
-		   ControlFile.checkPointCopy.undo.xlogid,
-		   ControlFile.checkPointCopy.undo.xrecoff);
 	printf(_("Latest checkpoint's TimeLineID:       %u\n"),
 		   ControlFile.checkPointCopy.ThisTimeLineID);
 	printf(_("Latest checkpoint's NextXID:          %u/%u\n"),
Index: src/bin/pg_resetxlog/pg_resetxlog.c
===================================================================
RCS file: /projects/cvsroot/pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v
retrieving revision 1.57
diff -a -u -r1.57 pg_resetxlog.c
--- src/bin/pg_resetxlog/pg_resetxlog.c	10 Feb 2007 14:58:55 -0000	1.57
+++ src/bin/pg_resetxlog/pg_resetxlog.c	23 Feb 2007 15:09:09 -0000
@@ -464,7 +464,6 @@
 
 	ControlFile.checkPointCopy.redo.xlogid = 0;
 	ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogLongPHD;
-	ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 	ControlFile.checkPointCopy.ThisTimeLineID = 1;
 	ControlFile.checkPointCopy.nextXidEpoch = 0;
 	ControlFile.checkPointCopy.nextXid = (TransactionId) 514;	/* XXX */
@@ -600,7 +599,6 @@
 	ControlFile.checkPointCopy.redo.xlogid = newXlogId;
 	ControlFile.checkPointCopy.redo.xrecoff =
 		newXlogSeg * XLogSegSize + SizeOfXLogLongPHD;
-	ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 	ControlFile.checkPointCopy.time = time(NULL);
 
 	ControlFile.state = DB_SHUTDOWNED;
Index: src/include/access/xlog_internal.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/access/xlog_internal.h,v
retrieving revision 1.18
diff -a -u -r1.18 xlog_internal.h
--- src/include/access/xlog_internal.h	5 Jan 2007 22:19:51 -0000	1.18
+++ src/include/access/xlog_internal.h	23 Feb 2007 15:09:09 -0000
@@ -71,7 +71,7 @@
 /*
  * Each page of XLOG file has a header like this:
  */
-#define XLOG_PAGE_MAGIC 0xD05E	/* can be used as WAL version indicator */
+#define XLOG_PAGE_MAGIC 0xD05F	/* can be used as WAL version indicator */
 
 typedef struct XLogPageHeaderData
 {
Index: src/include/catalog/pg_control.h
===================================================================
RCS file: /projects/cvsroot/pgsql/src/include/catalog/pg_control.h,v
retrieving revision 1.35
diff -a -u -r1.35 pg_control.h
--- src/include/catalog/pg_control.h	5 Jan 2007 22:19:52 -0000	1.35
+++ src/include/catalog/pg_control.h	23 Feb 2007 15:09:09 -0000
@@ -22,7 +22,7 @@
 
 
 /* Version identifier for this pg_control format */
-#define PG_CONTROL_VERSION	831
+#define PG_CONTROL_VERSION	832
 
 /*
  * Body of CheckPoint XLOG records.  This is declared here because we keep
@@ -32,9 +32,6 @@
 {
 	XLogRecPtr	redo;			/* next RecPtr available when we began to
 								 * create CheckPoint (i.e. REDO start point) */
-	XLogRecPtr	undo;			/* first record of oldest in-progress
-								 * transaction when we started (i.e. UNDO end
-								 * point) */
 	TimeLineID	ThisTimeLineID; /* current TLI */
 	uint32		nextXidEpoch;	/* higher-order bits of nextXid */
 	TransactionId nextXid;		/* next free XID */