diff --git a/src/backend/access/nbtree/nbtxlog.c b/src/backend/access/nbtree/nbtxlog.c
index ac60db0..4e3a825 100644
--- a/src/backend/access/nbtree/nbtxlog.c
+++ b/src/backend/access/nbtree/nbtxlog.c
@@ -135,7 +135,7 @@ _bt_clear_incomplete_split(XLogReaderState *record, uint8 block_id)
 		Page		page = (Page) BufferGetPage(buf);
 		BTPageOpaque pageop = (BTPageOpaque) PageGetSpecialPointer(page);
 
-		Assert((pageop->btpo_flags & BTP_INCOMPLETE_SPLIT) != 0);
+		Assert(P_INCOMPLETE_SPLIT(pageop));
 		pageop->btpo_flags &= ~BTP_INCOMPLETE_SPLIT;
 
 		PageSetLSN(page, lsn);
@@ -598,7 +598,7 @@ btree_xlog_delete_get_latestRemovedXid(XLogReaderState *record)
 			UnlockReleaseBuffer(ibuffer);
 			return InvalidTransactionId;
 		}
-		LockBuffer(hbuffer, BUFFER_LOCK_SHARE);
+		LockBuffer(hbuffer, BT_READ);
 		hpage = (Page) BufferGetPage(hbuffer);
 
 		/*
diff --git a/src/include/access/nbtree.h b/src/include/access/nbtree.h
index e6abbec..2d4c36d 100644
--- a/src/include/access/nbtree.h
+++ b/src/include/access/nbtree.h
@@ -173,14 +173,14 @@ typedef struct BTMetaPageData
  */
 #define P_LEFTMOST(opaque)		((opaque)->btpo_prev == P_NONE)
 #define P_RIGHTMOST(opaque)		((opaque)->btpo_next == P_NONE)
-#define P_ISLEAF(opaque)		((opaque)->btpo_flags & BTP_LEAF)
-#define P_ISROOT(opaque)		((opaque)->btpo_flags & BTP_ROOT)
-#define P_ISDELETED(opaque)		((opaque)->btpo_flags & BTP_DELETED)
-#define P_ISMETA(opaque)		((opaque)->btpo_flags & BTP_META)
-#define P_ISHALFDEAD(opaque)	((opaque)->btpo_flags & BTP_HALF_DEAD)
-#define P_IGNORE(opaque)		((opaque)->btpo_flags & (BTP_DELETED|BTP_HALF_DEAD))
-#define P_HAS_GARBAGE(opaque)	((opaque)->btpo_flags & BTP_HAS_GARBAGE)
-#define P_INCOMPLETE_SPLIT(opaque)	((opaque)->btpo_flags & BTP_INCOMPLETE_SPLIT)
+#define P_ISLEAF(opaque)		(((opaque)->btpo_flags & BTP_LEAF) != 0)
+#define P_ISROOT(opaque)		(((opaque)->btpo_flags & BTP_ROOT) != 0)
+#define P_ISDELETED(opaque)		(((opaque)->btpo_flags & BTP_DELETED) != 0)
+#define P_ISMETA(opaque)		(((opaque)->btpo_flags & BTP_META) != 0)
+#define P_ISHALFDEAD(opaque)	(((opaque)->btpo_flags & BTP_HALF_DEAD) != 0)
+#define P_IGNORE(opaque)		(((opaque)->btpo_flags & (BTP_DELETED|BTP_HALF_DEAD)) != 0)
+#define P_HAS_GARBAGE(opaque)	(((opaque)->btpo_flags & BTP_HAS_GARBAGE) != 0)
+#define P_INCOMPLETE_SPLIT(opaque)	(((opaque)->btpo_flags & BTP_INCOMPLETE_SPLIT) != 0)
 
 /*
  *	Lehman and Yao's algorithm requires a ``high key'' on every non-rightmost