From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Fri, 6 Jan 2006 00:15:58 +0000 (+0000)
Subject: Convert Assert checking for empty page into a regular test and elog.
X-Git-Url: http://waps.l3s.uni-hannover.de/gitweb/?a=commitdiff_plain;h=46e1182f922f2aacca928578b2f3e7eaaa7abcf5;p=users%2Fbernd%2Fpostgres.git

Convert Assert checking for empty page into a regular test and elog.
The consequences of overwriting a non-empty page are bad enough that
we should not omit this test in production builds.
---

diff --git a/src/backend/access/heap/hio.c b/src/backend/access/heap/hio.c
index 116dcb71d3..6481493f3a 100644
--- a/src/backend/access/heap/hio.c
+++ b/src/backend/access/heap/hio.c
@@ -281,10 +281,17 @@ RelationGetBufferForTuple(Relation relation, Size len,
 		UnlockRelationForExtension(relation, ExclusiveLock);
 
 	/*
-	 * We need to initialize the empty new page.
+	 * We need to initialize the empty new page.  Double-check that it really
+	 * is empty (this should never happen, but if it does we don't want to
+	 * risk wiping out valid data).
 	 */
 	pageHeader = (Page) BufferGetPage(buffer);
-	Assert(PageIsNew((PageHeader) pageHeader));
+
+	if (!PageIsNew((PageHeader) pageHeader))
+		elog(ERROR, "page %u of relation \"%s\" should be empty but is not",
+			 BufferGetBlockNumber(buffer),
+			 RelationGetRelationName(relation));
+
 	PageInit(pageHeader, BufferGetPageSize(buffer), 0);
 
 	if (len > PageGetFreeSpace(pageHeader))