Releasing empty root page in _bt_endpoint () to avoid

buffer leak.

diff --git a/src/backend/access/nbtree/nbtsearch.c b/src/backend/access/nbtree/nbtsearch.c
index 9c07114bc476688003754cee6787153375622dfa..569a9e7e7f88c07a87c6fc67e8bb15cd9f15a62a 100644 (file)
--- a/src/backend/access/nbtree/nbtsearch.c
+++ b/src/backend/access/nbtree/nbtsearch.c
@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *    $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtsearch.c,v 1.12 1996/12/15 09:05:10 bryanh Exp $
+ *    $Header: /cvsroot/pgsql/src/backend/access/nbtree/nbtsearch.c,v 1.13 1997/01/05 10:56:36 vadim Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1080,6 +1080,7 @@ _bt_endpoint(IndexScanDesc scan, ScanDirection dir)
     
     rel = scan->relation;
     current = &(scan->currentItemData);
+    so = (BTScanOpaque) scan->opaque;
     
     buf = _bt_getroot(rel, BT_READ);
     blkno = BufferGetBlockNumber(buf);
@@ -1153,6 +1154,9 @@ _bt_endpoint(IndexScanDesc scan, ScanDirection dir)
        if ( start != P_HIKEY ) /* non-rightmost page */
        elog (WARN, "_bt_endpoint: non-rightmost page (%u) is empty", blkno);
        /* It's left- & right- most page - root page, - and it's empty... */
+       _bt_relbuf(rel, buf, BT_READ);
+       ItemPointerSetInvalid(current);
+       so->btso_curbuf = InvalidBuffer;
        return ((RetrieveIndexResult) NULL);
    }
    if ( start > maxoff )       /* start == 2 && maxoff == 1 */
@@ -1188,7 +1192,12 @@ _bt_endpoint(IndexScanDesc scan, ScanDirection dir)
    {
        /* If it's leftmost page too - it's empty root page... */
        if ( P_LEFTMOST(opaque) )
+       {
+       _bt_relbuf(rel, buf, BT_READ);
+       ItemPointerSetInvalid(current);
+       so->btso_curbuf = InvalidBuffer;
            return ((RetrieveIndexResult) NULL);
+       }
        /* Go back ! */
        ItemPointerSet(current, blkno, FirstOffsetNumber);
        if (!_bt_step(scan, &buf, BackwardScanDirection))
@@ -1214,7 +1223,6 @@ _bt_endpoint(IndexScanDesc scan, ScanDirection dir)
    res = FormRetrieveIndexResult(current, &(itup->t_tid));
    
    /* remember which buffer we have pinned */
-   so = (BTScanOpaque) scan->opaque;
    so->btso_curbuf = buf;
     } else {
    _bt_relbuf(rel, buf, BT_READ);