Repair a number of places that didn't bother to check whether PageAddItem

succeeds or not.  Revise rtree page split algorithm to take care about
making a feasible split --- ie, will the incoming tuple actually fit?
Failure to make a feasible split, combined with failure to notice the
failure, account for Jim Stone's recent bug report.  I suspect that
hash and gist indices may have the same type of bug, but at least now
we'll get error messages rather than silent failures if so.  Also clean
up rtree code to use Datum rather than char* where appropriate.

src/backend/access/gist/gist.c

@@ -6,7 +6,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/gist/gist.c,v 1.70 2001/02/22 21:48:48 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/gist/gist.c,v 1.71 2001/03/07 21:20:26 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -395,6 +395,9 @@ gistPageAddItem(GISTSTATE *giststate,
 	*newtup = gist_tuple_replacekey(r, tmpcentry, itup);
 	retval = PageAddItem(page, (Item) *newtup, IndexTupleSize(*newtup),
 						offsetNumber, flags);
+	if (retval == InvalidOffsetNumber)
+		elog(ERROR, "gist: failed to add index item to %s",
+			 RelationGetRelationName(r));
 	/* be tidy */
 	if (tmpcentry.pred && tmpcentry.pred != dentry->pred
 		&& tmpcentry.pred != (((char *) itup) + sizeof(IndexTupleData)))

src/backend/access/hash/hashinsert.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/hash/hashinsert.c,v 1.21 2001/01/24 19:42:47 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/hash/hashinsert.c,v 1.22 2001/03/07 21:20:26 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -230,7 +230,10 @@ _hash_pgaddtup(Relation rel,
 	_hash_checkpage(page, LH_BUCKET_PAGE | LH_OVERFLOW_PAGE);
 
 	itup_off = OffsetNumberNext(PageGetMaxOffsetNumber(page));
-	PageAddItem(page, (Item) hitem, itemsize, itup_off, LP_USED);
+	if (PageAddItem(page, (Item) hitem, itemsize, itup_off, LP_USED)
+		== InvalidOffsetNumber)
+		elog(ERROR, "_hash_pgaddtup: failed to add index item to %s",
+			 RelationGetRelationName(rel));
 
 	/* write the buffer, but hold our lock */
 	_hash_wrtnorelbuf(rel, buf);

src/backend/access/hash/hashovfl.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/hash/hashovfl.c,v 1.28 2001/01/24 19:42:47 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/hash/hashovfl.c,v 1.29 2001/03/07 21:20:26 tgl Exp $
  *
  * NOTES
  *	  Overflow pages look like ordinary relation pages.
@@ -564,7 +564,10 @@ _hash_squeezebucket(Relation rel,
 		 * page.
 		 */
 		woffnum = OffsetNumberNext(PageGetMaxOffsetNumber(wpage));
-		PageAddItem(wpage, (Item) hitem, itemsz, woffnum, LP_USED);
+		if (PageAddItem(wpage, (Item) hitem, itemsz, woffnum, LP_USED)
+			== InvalidOffsetNumber)
+			elog(ERROR, "_hash_squeezebucket: failed to add index item to %s",
+				 RelationGetRelationName(rel));
 
 		/*
 		 * delete the tuple from the "read" page. PageIndexTupleDelete

src/backend/access/hash/hashpage.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/access/hash/hashpage.c,v 1.29 2001/01/24 19:42:47 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/access/hash/hashpage.c,v 1.30 2001/03/07 21:20:26 tgl Exp $
  *
  * NOTES
  *	  Postgres hash pages look like ordinary relation pages.  The opaque
@@ -619,7 +619,10 @@ _hash_splitpage(Relation rel,
 			}
 
 			noffnum = OffsetNumberNext(PageGetMaxOffsetNumber(npage));
-			PageAddItem(npage, (Item) hitem, itemsz, noffnum, LP_USED);
+			if (PageAddItem(npage, (Item) hitem, itemsz, noffnum, LP_USED)
+				== InvalidOffsetNumber)
+				elog(ERROR, "_hash_splitpage: failed to add index item to %s",
+					 RelationGetRelationName(rel));
 			_hash_wrtnorelbuf(rel, nbuf);
 
 			/*

src/backend/commands/sequence.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/sequence.c,v 1.50 2001/02/13 01:57:12 pjw Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/sequence.c,v 1.51 2001/03/07 21:20:26 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -785,7 +785,8 @@ void seq_redo(XLogRecPtr lsn, XLogRecord *record)
 	itemsz = record->xl_len - sizeof(xl_seq_rec);
 	itemsz = MAXALIGN(itemsz);
 	if (PageAddItem(page, (Item)item, itemsz, 
-			FirstOffsetNumber, LP_USED) == InvalidOffsetNumber)
+					FirstOffsetNumber, LP_USED) == InvalidOffsetNumber)
+		elog(STOP, "seq_redo: failed to add item to page");
 
 	PageSetLSN(page, lsn);
 	PageSetSUI(page, ThisStartUpID);