From c6e010a872546c82f8a4280c954c985e8fbe2053 Mon Sep 17 00:00:00 2001
From: Leo Yuriev <leo@yuriev.ru>
Date: Sat, 31 Oct 2015 13:56:12 +0300
Subject: [PATCH] mdbx: fix segfault on close when open failed.

---
 mdb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mdb.c b/mdb.c
index e4f45e6b..5e66e0a9 100644
--- a/mdb.c
+++ b/mdb.c
@@ -4899,6 +4899,7 @@ mdb_env_close0(MDB_env *env)
 	mdb_coherent_barrier();
 	mdb_ensure(env, pthread_mutex_unlock(&mdb_rthc_lock) == 0);
 	munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
+	env->me_txns = NULL;
 
 	if (env->me_lfd != INVALID_HANDLE_VALUE) {
 		(void) close(env->me_lfd);
@@ -4921,7 +4922,7 @@ mdbx_env_close_ex(MDB_env *env, int dont_sync)
 	if (unlikely(env->me_signature != MDBX_ME_SIGNATURE))
 		return MDB_VERSION_MISMATCH;
 
-	if (! dont_sync)
+	if (! dont_sync && env->me_txns)
 		rc = mdb_env_sync(env, 1);
 
 	VALGRIND_DESTROY_MEMPOOL(env);