Fix coredump during replay WAL after crash. Change entrySplitPage() to prevent

usage of any information from system catalog, because it could be called during
replay of WAL.

Per bug report from Craig McElroy <craig.mcelroy@contegix.com>. Patch doesn't
change on-disk storage.

Author: feodor

src/backend/access/gin/ginentrypage.c

@@ -8,7 +8,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *			$PostgreSQL: pgsql/src/backend/access/gin/ginentrypage.c,v 1.9 2007/09/20 17:56:30 tgl Exp $
+ *			$PostgreSQL: pgsql/src/backend/access/gin/ginentrypage.c,v 1.10 2007/10/29 13:49:21 teodor Exp $
  *-------------------------------------------------------------------------
  */
 
@@ -403,6 +403,31 @@ entryPlaceToPage(GinBtree btree, Buffer buf, OffsetNumber off, XLogRecData **prd
 	btree->entry = NULL;
 }
 
+/*
+ * Returns new tuple with copied value from source tuple.
+ * New tuple will not store posting list
+ */
+static IndexTuple
+copyIndexTuple(IndexTuple itup, Page page)
+{
+	IndexTuple	nitup;
+
+	if (GinPageIsLeaf(page) && !GinIsPostingTree(itup))
+	{
+		nitup = (IndexTuple) palloc(MAXALIGN(GinGetOrigSizePosting(itup)));
+		memcpy(nitup, itup, GinGetOrigSizePosting(itup));
+		nitup->t_info &= ~INDEX_SIZE_MASK;
+		nitup->t_info |= GinGetOrigSizePosting(itup);
+	}
+	else
+	{
+		nitup = (IndexTuple) palloc(MAXALIGN(IndexTupleSize(itup)));
+		memcpy(nitup, itup, IndexTupleSize(itup));
+	}
+
+	return nitup;
+}
+
 /*
  * Place tuple and split page, original buffer(lbuf) leaves untouched,
  * returns shadow page of lbuf filled new data.
@@ -424,8 +449,6 @@ entrySplitPage(GinBtree btree, Buffer lbuf, Buffer rbuf, OffsetNumber off, XLogR
 	IndexTuple	itup,
 				leftrightmost = NULL;
 	static ginxlogSplit data;
-	Datum		value;
-	bool		isnull;
 	Page		page;
 	Page		lpage = GinPageGetCopyPage(BufferGetPage(lbuf));
 	Page		rpage = BufferGetPage(rbuf);
@@ -494,9 +517,9 @@ entrySplitPage(GinBtree btree, Buffer lbuf, Buffer rbuf, OffsetNumber off, XLogR
 		ptr += MAXALIGN(IndexTupleSize(itup));
 	}
 
-	value = index_getattr(leftrightmost, FirstOffsetNumber, btree->ginstate->tupdesc, &isnull);
-	btree->entry = GinFormTuple(btree->ginstate, value, NULL, 0);
+	btree->entry = copyIndexTuple(leftrightmost, lpage);
 	ItemPointerSet(&(btree->entry)->t_tid, BufferGetBlockNumber(lbuf), InvalidOffsetNumber);
+
 	btree->rightblkno = BufferGetBlockNumber(rbuf);
 
 	data.node = btree->index->rd_node;
@@ -533,20 +556,9 @@ ginPageGetLinkItup(Buffer buf)
 	Page		page = BufferGetPage(buf);
 
 	itup = getRightMostTuple(page);
-	if (GinPageIsLeaf(page) && !GinIsPostingTree(itup))
-	{
-		nitup = (IndexTuple) palloc(MAXALIGN(GinGetOrigSizePosting(itup)));
-		memcpy(nitup, itup, GinGetOrigSizePosting(itup));
-		nitup->t_info &= ~INDEX_SIZE_MASK;
-		nitup->t_info |= GinGetOrigSizePosting(itup);
-	}
-	else
-	{
-		nitup = (IndexTuple) palloc(MAXALIGN(IndexTupleSize(itup)));
-		memcpy(nitup, itup, IndexTupleSize(itup));
-	}
-
+	nitup = copyIndexTuple(itup, page);
 	ItemPointerSet(&nitup->t_tid, BufferGetBlockNumber(buf), InvalidOffsetNumber);
+
 	return nitup;
 }