Merge pull request #2161 from EOSIO/chainbase_txn_container_expiry_ordering

Fix DB memory leak in transaction containers

libraries/chain/chain_controller.cpp

@@ -1885,15 +1885,16 @@ void chain_controller::clear_expired_transactions()
    //transactions must have expired by at least two forking windows in order to be removed.
    auto& transaction_idx = _db.get_mutable_index<transaction_multi_index>();
    const auto& dedupe_index = transaction_idx.indices().get<by_expiration>();
-   while( (!dedupe_index.empty()) && (head_block_time() > fc::time_point(dedupe_index.rbegin()->expiration) ) )
-      transaction_idx.remove(*dedupe_index.rbegin());
+   while( (!dedupe_index.empty()) && (head_block_time() > fc::time_point(dedupe_index.begin()->expiration) ) ) {
+      transaction_idx.remove(*dedupe_index.begin());
+   }
 
    //Look for expired transactions in the pending generated list, and remove them.
    //transactions must have expired by at least two forking windows in order to be removed.
    auto& generated_transaction_idx = _db.get_mutable_index<generated_transaction_multi_index>();
    const auto& generated_index = generated_transaction_idx.indices().get<by_expiration>();
-   while( (!generated_index.empty()) && (head_block_time() > generated_index.rbegin()->expiration) ) {
-      _destroy_generated_transaction(*generated_index.rbegin());
+   while( (!generated_index.empty()) && (head_block_time() > generated_index.begin()->expiration) ) {
+      _destroy_generated_transaction(*generated_index.begin());
    }
 
 } FC_CAPTURE_AND_RETHROW() }