Bug#23320254 TEST CASES ARE CONSTANTLY HANGING AND GENERATE MEMORY LEAKS (post-fix)

Problem
-------
The method Gcs_xcom_state_exchange::process_member_state overwrites an owned pointer without deleting it first, so it leaks.

Solution
--------
If it exists, delete the existing pointer before overwriting it.

Reviewed-by: Andre Negrao <[email protected]>
Reviewed-by: Tiago Jorge <[email protected]>
RB: 20141

Author: tvale

rapid/plugin/group_replication/libmysqlgcs/src/bindings/xcom/gcs_xcom_state_exchange.cc

@@ -618,7 +618,7 @@ process_member_state(Xcom_member_state *ms_info,
     return false;
   }
 
-  m_member_states[p_id]= ms_info;
+  save_member_state(ms_info, p_id);
 
   /*
     The rule of updating the awaited_vector at receiving is simply to
@@ -647,6 +647,17 @@ fill_member_set(std::vector<Gcs_member_identifier *> &in,
   std::copy(in.begin(), in.end(), std::inserter(pset, pset.begin()));
 }
 
+void Gcs_xcom_state_exchange::save_member_state(
+    Xcom_member_state *ms_info, const Gcs_member_identifier &p_id) {
+  /* m_member_states[p_id] may already exist. In that case we delete the
+   * existing pointer, otherwise it leaks. */
+  std::map<Gcs_member_identifier, Xcom_member_state *>::iterator
+      member_state_it = m_member_states.find(p_id);
+  bool const state_already_exists = (member_state_it != m_member_states.end());
+  if (state_already_exists) delete member_state_it->second;
+  m_member_states[p_id] = ms_info;
+}
+
 
 Gcs_xcom_view_identifier *
 Gcs_xcom_state_exchange::get_new_view_id()

rapid/plugin/group_replication/libmysqlgcs/src/bindings/xcom/gcs_xcom_state_exchange.h

@@ -1,4 +1,4 @@
-/* Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.
+/* Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
 
    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -506,6 +506,16 @@ class Gcs_xcom_state_exchange: public Gcs_xcom_state_exchange_interface
   void fill_member_set(std::vector<Gcs_member_identifier *> &in,
                        std::set<Gcs_member_identifier *> &pset);
 
+  /**
+   * Stores the member's state and protocol version.
+   *
+   * @param ms_info state
+   * @param p_id member
+   * @param protocol_version protocol version
+   */
+  void save_member_state(Xcom_member_state *ms_info,
+                         const Gcs_member_identifier &p_id);
+
   Gcs_communication_interface *m_broadcaster;
 
   std::map<Gcs_member_identifier, uint> m_awaited_vector;