There is no need for ReadBuffer() call sites to check that the returned

buffer is valid, as ReadBuffer() will elog on error. Most of the call
sites of ReadBuffer() got this right, but this patch fixes those call
sites that did not.

src/backend/access/heap/heapam.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.180 2004/10/26 16:05:02 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/access/heap/heapam.c,v 1.181 2004/11/14 02:04:12 neilc Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -191,8 +191,6 @@ heapgettup(Relation relation,
 		*buffer = ReleaseAndReadBuffer(*buffer,
 									   relation,
 									   ItemPointerGetBlockNumber(tid));
-		if (!BufferIsValid(*buffer))
-			elog(ERROR, "ReadBuffer failed");
 
 		LockBuffer(*buffer, BUFFER_LOCK_SHARE);
 
@@ -226,8 +224,6 @@ heapgettup(Relation relation,
 		*buffer = ReleaseAndReadBuffer(*buffer,
 									   relation,
 									   page);
-		if (!BufferIsValid(*buffer))
-			elog(ERROR, "ReadBuffer failed");
 
 		LockBuffer(*buffer, BUFFER_LOCK_SHARE);
 
@@ -266,8 +262,6 @@ heapgettup(Relation relation,
 		*buffer = ReleaseAndReadBuffer(*buffer,
 									   relation,
 									   page);
-		if (!BufferIsValid(*buffer))
-			elog(ERROR, "ReadBuffer failed");
 
 		LockBuffer(*buffer, BUFFER_LOCK_SHARE);
 
@@ -360,8 +354,6 @@ heapgettup(Relation relation,
 		*buffer = ReleaseAndReadBuffer(*buffer,
 									   relation,
 									   page);
-		if (!BufferIsValid(*buffer))
-			elog(ERROR, "ReadBuffer failed");
 
 		LockBuffer(*buffer, BUFFER_LOCK_SHARE);
 		dp = (Page) BufferGetPage(*buffer);
@@ -941,11 +933,6 @@ heap_release_fetch(Relation relation,
 	buffer = ReleaseAndReadBuffer(*userbuf, relation,
 								  ItemPointerGetBlockNumber(tid));
 
-	if (!BufferIsValid(buffer))
-		elog(ERROR, "ReadBuffer(\"%s\", %lu) failed",
-			 RelationGetRelationName(relation),
-			 (unsigned long) ItemPointerGetBlockNumber(tid));
-
 	/*
 	 * Need share lock on buffer to examine tuple commit status.
 	 */
@@ -1049,14 +1036,7 @@ heap_get_latest_tid(Relation relation,
 	 * get the buffer from the relation descriptor Note that this does a
 	 * buffer pin.
 	 */
-
 	buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
-
-	if (!BufferIsValid(buffer))
-		elog(ERROR, "ReadBuffer(\"%s\", %lu) failed",
-			 RelationGetRelationName(relation),
-			 (unsigned long) ItemPointerGetBlockNumber(tid));
-
 	LockBuffer(buffer, BUFFER_LOCK_SHARE);
 
 	/*
@@ -1304,10 +1284,6 @@ heap_delete(Relation relation, ItemPointer tid,
 	Assert(ItemPointerIsValid(tid));
 
 	buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
-
-	if (!BufferIsValid(buffer))
-		elog(ERROR, "ReadBuffer failed");
-
 	LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
 
 	dp = (PageHeader) BufferGetPage(buffer);
@@ -1528,8 +1504,6 @@ heap_update(Relation relation, ItemPointer otid, HeapTuple newtup,
 	Assert(ItemPointerIsValid(otid));
 
 	buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(otid));
-	if (!BufferIsValid(buffer))
-		elog(ERROR, "ReadBuffer failed");
 	LockBuffer(buffer, BUFFER_LOCK_EXCLUSIVE);
 
 	dp = (PageHeader) BufferGetPage(buffer);
@@ -1863,10 +1837,6 @@ heap_mark4update(Relation relation, HeapTuple tuple, Buffer *buffer,
 	int			result;
 
 	*buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
-
-	if (!BufferIsValid(*buffer))
-		elog(ERROR, "ReadBuffer failed");
-
 	LockBuffer(*buffer, BUFFER_LOCK_EXCLUSIVE);
 
 	dp = (PageHeader) BufferGetPage(*buffer);

src/backend/commands/analyze.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/analyze.c,v 1.78 2004/10/26 16:05:03 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/analyze.c,v 1.79 2004/11/14 02:04:13 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -811,8 +811,6 @@ acquire_sample_rows(Relation onerel, HeapTuple *rows, int targrows,
 		 * tuples.
 		 */
 		targbuffer = ReadBuffer(onerel, targblock);
-		if (!BufferIsValid(targbuffer))
-			elog(ERROR, "ReadBuffer failed");
 		LockBuffer(targbuffer, BUFFER_LOCK_SHARE);
 		targpage = BufferGetPage(targbuffer);
 		maxoffset = PageGetMaxOffsetNumber(targpage);

src/backend/commands/sequence.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.117 2004/09/16 16:58:28 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/sequence.c,v 1.118 2004/11/14 02:04:14 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -192,10 +192,6 @@ DefineSequence(CreateSeqStmt *seq)
 	/* Initialize first page of relation with special magic number */
 
 	buf = ReadBuffer(rel, P_NEW);
-
-	if (!BufferIsValid(buf))
-		elog(ERROR, "ReadBuffer failed");
-
 	Assert(BufferGetBlockNumber(buf) == 0);
 
 	page = (PageHeader) BufferGetPage(buf);
@@ -850,9 +846,6 @@ read_info(SeqTable elm, Relation rel, Buffer *buf)
 	Form_pg_sequence seq;
 
 	*buf = ReadBuffer(rel, 0);
-	if (!BufferIsValid(*buf))
-		elog(ERROR, "ReadBuffer failed");
-
 	LockBuffer(*buf, BUFFER_LOCK_EXCLUSIVE);
 
 	page = (PageHeader) BufferGetPage(*buf);

src/backend/commands/trigger.c

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.174 2004/10/30 20:52:56 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/trigger.c,v 1.175 2004/11/14 02:04:14 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1625,9 +1625,6 @@ ltrmark:;
 
 		buffer = ReadBuffer(relation, ItemPointerGetBlockNumber(tid));
 
-		if (!BufferIsValid(buffer))
-			elog(ERROR, "ReadBuffer failed");
-
 		dp = (PageHeader) BufferGetPage(buffer);
 		lp = PageGetItemId(dp, ItemPointerGetOffsetNumber(tid));