Fix longstanding bug found by Atsushi Ogawa: _bt_check_unique would mark

the wrong buffer dirty when trying to kill a dead index entry that's on
a page after the one it started on.  No risk of data corruption, just
inefficiency, but still a bug.

diff --git a/src/backend/access/nbtree/nbtinsert.c b/src/backend/access/nbtree/nbtinsert.c
index f85200328eb552b04fc0807e51a81a96ecf360d3..184be5765f2c4fadc7b6850cd3bdf986006431b9 100644 (file)
--- a/src/backend/access/nbtree/nbtinsert.c
+++ b/src/backend/access/nbtree/nbtinsert.c
@@ -270,7 +270,10 @@ _bt_check_unique(Relation rel, BTItem btitem, Relation heapRel,
                                                HEAPTUPLE_DEAD)
                                        {
                                                curitemid->lp_flags |= LP_DELETE;
-                                               SetBufferCommitInfoNeedsSave(buf);
+                                               if (nbuf != InvalidBuffer)
+                                                       SetBufferCommitInfoNeedsSave(nbuf);
+                                               else
+                                                       SetBufferCommitInfoNeedsSave(buf);
                                        }
                                        if (sv_infomask != htup.t_data->t_infomask)
                                                SetBufferCommitInfoNeedsSave(hbuffer);