ITS#8157 mdb_txn_renew0(): init after error checks

libraries/liblmdb/mdb.c

@@ -2581,15 +2581,11 @@ mdb_txn_renew0(MDB_txn *txn)
 	MDB_env *env = txn->mt_env;
 	MDB_txninfo *ti = env->me_txns;
 	MDB_meta *meta;
-	unsigned int i, nr;
+	unsigned int i, nr, flags = txn->mt_flags;
 	uint16_t x;
 	int rc, new_notls = 0;
 
-	if (txn->mt_flags & MDB_TXN_RDONLY) {
+	if ((flags &= MDB_TXN_RDONLY) != 0) {
-		txn->mt_flags = MDB_TXN_RDONLY;
-		/* Setup db info */
-		txn->mt_numdbs = env->me_numdbs;
-		txn->mt_dbxs = env->me_dbxs;	/* mostly static anyway */
 		if (!ti) {
 			meta = env->me_metas[ mdb_env_pick_meta(env) ];
 			txn->mt_txnid = meta->mm_txnid;
@@ -2651,6 +2647,7 @@ mdb_txn_renew0(MDB_txn *txn)
 			txn->mt_u.reader = r;
 			meta = env->me_metas[txn->mt_txnid & 1];
 		}
+		txn->mt_dbxs = env->me_dbxs;	/* mostly static anyway */
 	} else {
 		/* Not yet touching txn == env->me_txn0, it may be active */
 		if (ti) {
@@ -2662,14 +2659,11 @@ mdb_txn_renew0(MDB_txn *txn)
 			meta = env->me_metas[ mdb_env_pick_meta(env) ];
 			txn->mt_txnid = meta->mm_txnid;
 		}
-		/* Setup db info */
-		txn->mt_numdbs = env->me_numdbs;
 		txn->mt_txnid++;
 #if MDB_DEBUG
 		if (txn->mt_txnid == mdb_debug_start)
 			mdb_debug = 1;
 #endif
-		txn->mt_flags = 0;
 		txn->mt_child = NULL;
 		txn->mt_loose_pgs = NULL;
 		txn->mt_loose_count = 0;
@@ -2689,6 +2683,10 @@ mdb_txn_renew0(MDB_txn *txn)
 	/* Moved to here to avoid a data race in read TXNs */
 	txn->mt_next_pgno = meta->mm_last_pg+1;
 
+	txn->mt_flags = flags;
+
+	/* Setup db info */
+	txn->mt_numdbs = env->me_numdbs;
 	for (i=2; i<txn->mt_numdbs; i++) {
 		x = env->me_dbflags[i];
 		txn->mt_dbs[i].md_flags = x & PERSISTENT_FLAGS;