env:txn_begin(): make read-only by default

this is more sensible behavior. read-write transactions are less
performant, so the programmer should have to engage them explicitly.

1 files changed, 1 insertions, 1 deletions

diff --git a/lmdb.c b/lmdb.c
index 1a2c27a..5bcf162 100644
--- a/lmdb.c
+++ b/lmdb.c
@@ -146,7 +146,7 @@ static int txn_begin(lua_State *L, bool nested) {
 	
 	MDB_txn *txn;
 	reterr(mdb_txn_begin(
-		env, parent, lua_toboolean(L, 2) ? MDB_RDONLY : 0, &txn));
+		env, parent, lua_toboolean(L, 2) || nested ? 0 : MDB_RDONLY, &txn));
 
 	struct handle *tud = lua_newuserdata(L, sizeof(struct handle));
 	tud->closed = false;