WAL need in overwrite mode - restored in new way

(without PageManagetSetMode -:))
Safe shuffle mode behaviour retained.

diff --git a/src/backend/storage/page/bufpage.c b/src/backend/storage/page/bufpage.c
index 1a970a137514a3bf5c8ae010ed837e25bef32030..dd1b44d334cd32deb9d78ee49eac5586aee6a9a2 100644 (file)
--- a/src/backend/storage/page/bufpage.c
+++ b/src/backend/storage/page/bufpage.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $Header: /cvsroot/pgsql/src/backend/storage/page/bufpage.c,v 1.31 2000/07/21 06:42:33 tgl Exp $
+ *       $Header: /cvsroot/pgsql/src/backend/storage/page/bufpage.c,v 1.32 2000/10/20 11:28:39 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -80,6 +80,9 @@ PageAddItem(Page page,
        ItemId          itemId;
        OffsetNumber limit;
        bool            needshuffle = false;
+       bool            overwritemode = flags & OverwritePageMode;
+
+       flags &= ~OverwritePageMode;
 
        /*
         * Find first unallocated offsetNumber
@@ -89,8 +92,28 @@ PageAddItem(Page page,
        /* was offsetNumber passed in? */
        if (OffsetNumberIsValid(offsetNumber))
        {
-               needshuffle = true;             /* need to increase "lower" */
-               /* don't actually do the shuffle till we've checked free space! */
+               if (overwritemode)
+               {
+                       if (offsetNumber > limit)
+                       {
+                               elog(NOTICE, "PageAddItem: tried overwrite after maxoff");
+                               return InvalidOffsetNumber;
+                       }
+                       itemId = &((PageHeader) page)->pd_linp[offsetNumber - 1];
+                       if (((*itemId).lp_flags & LP_USED) ||
+                               ((*itemId).lp_len != 0))
+                       {
+                               elog(NOTICE, "PageAddItem: tried overwrite of used ItemId");
+                               return InvalidOffsetNumber;
+                       }
+               }
+               else
+               {
+                       /*
+                        * Don't actually do the shuffle till we've checked free space!
+                        */
+                       needshuffle = true;             /* need to increase "lower" */
+               }
        }
        else
        {