From 9d75a82ae10fdcee80b8b8e82c6ef9b6ab83dc47 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@openldap.org>
Date: Tue, 22 Dec 2015 06:13:25 +0000
Subject: [PATCH] MDB_VL32 - fix prev commit

Only tweak length for read-only envs
---
 libraries/liblmdb/mdb.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 516e69a..4ff4950 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -5803,8 +5803,8 @@ retry:
 		id3.mref = 1;
 		if (id3.mid)
 			goto found;
-		/* don't map past last written page */
-		if (pgno + MDB_RPAGE_CHUNK-1 > txn->mt_last_pgno)
+		/* don't map past last written page in read-only envs */
+		if ((env->me_flags & MDB_RDONLY) && pgno + MDB_RPAGE_CHUNK-1 > txn->mt_last_pgno)
 			id3.mcnt = txn->mt_last_pgno + 1 - pgno;
 		else
 			id3.mcnt = MDB_RPAGE_CHUNK;