BUG#26634 (Valgrind failure in tree: memory loss for memory allocated in rpl_utility.h):

Adding code to release allocated memory when tables_to_lock list is
cleared.

sql/log_event.cc

@@ -5783,10 +5783,10 @@ int Rows_log_event::exec_event(st_relay_log_info *rli)
         need to add code to assert that is the case.
        */
       thd->binlog_flush_pending_rows_event(false);
-      close_tables_for_reopen(thd, &rli->tables_to_lock);
+      TABLE_LIST *tables= rli->tables_to_lock;
+      close_tables_for_reopen(thd, &tables);
 
-      if ((error= open_tables(thd, &rli->tables_to_lock,
-                              &rli->tables_to_lock_count, 0)))
+      if ((error= open_tables(thd, &tables, &rli->tables_to_lock_count, 0)))
       {
         if (thd->query_error || thd->is_fatal_error)
         {
@@ -5815,7 +5815,7 @@ int Rows_log_event::exec_event(st_relay_log_info *rli)
     */
 
     {
-      RPL_TABLE_LIST *ptr= static_cast<RPL_TABLE_LIST*>(rli->tables_to_lock);
+      RPL_TABLE_LIST *ptr= rli->tables_to_lock;
       for ( ; ptr ; ptr= static_cast<RPL_TABLE_LIST*>(ptr->next_global))
       {
         if (ptr->m_tabledef.compatible_with(rli, ptr->table))
@@ -6396,9 +6396,15 @@ int Table_map_log_event::exec_event(st_relay_log_info *rli)
     /*
       Use placement new to construct the table_def instance in the
       memory allocated for it inside table_list.
+
+      The memory allocated by the table_def structure (i.e., not the
+      memory allocated *for* the table_def structure) is released
+      inside st_relay_log_info::clear_tables_to_lock() by calling the
+      table_def destructor explicitly.
     */
     const table_def *const def=
       new (&table_list->m_tabledef) table_def(m_coltype, m_colcnt);
+    table_list->m_tabledef_valid= TRUE;
 
     /*
       We record in the slave's information that the table should be

sql/rpl_rli.cc

@@ -18,6 +18,7 @@
 #include "rpl_rli.h"
 #include <my_dir.h>    // For MY_STAT
 #include "sql_repl.h"  // For check_binlog_magic
+#include "rpl_utility.h"
 
 static int count_relay_log_space(RELAY_LOG_INFO* rli);
 
@@ -1108,4 +1109,23 @@ void st_relay_log_info::cleanup_context(THD *thd, bool error)
   unsafe_to_stop_at= 0;
   DBUG_VOID_RETURN;
 }
+
+void st_relay_log_info::clear_tables_to_lock()
+{
+  while (tables_to_lock)
+  {
+    gptr to_free= reinterpret_cast<gptr>(tables_to_lock);
+    if (tables_to_lock->m_tabledef_valid)
+    {
+      tables_to_lock->m_tabledef.table_def::~table_def();
+      tables_to_lock->m_tabledef_valid= FALSE;
+    }
+    tables_to_lock=
+      static_cast<RPL_TABLE_LIST*>(tables_to_lock->next_global);
+    tables_to_lock_count--;
+    my_free(to_free, MYF(MY_WME));
+  }
+  DBUG_ASSERT(tables_to_lock == NULL && tables_to_lock_count == 0);
+}
+
 #endif

sql/rpl_rli.h

@@ -20,6 +20,8 @@
 
 #include "rpl_tblmap.h"
 
+struct RPL_TABLE_LIST;
+
 
 /****************************************************************************
 
@@ -279,7 +281,7 @@ typedef struct st_relay_log_info
 	    group_relay_log_pos);
   }
 
-  TABLE_LIST *tables_to_lock;               /* RBR: Tables to lock  */
+  RPL_TABLE_LIST *tables_to_lock;           /* RBR: Tables to lock  */
   uint tables_to_lock_count;        /* RBR: Count of tables to lock */
   table_mapping m_table_map;      /* RBR: Mapping table-id to table */
 
@@ -295,16 +297,7 @@ typedef struct st_relay_log_info
   void transaction_end(THD*);
 
   void cleanup_context(THD *, bool);
-  void clear_tables_to_lock() {
-    while (tables_to_lock)
-    {
-      char *to_free= reinterpret_cast<gptr>(tables_to_lock);
-      tables_to_lock= tables_to_lock->next_global;
-      tables_to_lock_count--;
-      my_free(to_free, MYF(MY_WME));
-    }
-    DBUG_ASSERT(tables_to_lock == NULL && tables_to_lock_count == 0);
-  }
+  void clear_tables_to_lock();
 
   time_t unsafe_to_stop_at;
 } RELAY_LOG_INFO;

sql/rpl_utility.h

@@ -22,6 +22,9 @@
 
 #include "mysql_priv.h"
 
+struct st_relay_log_info;
+typedef st_relay_log_info RELAY_LOG_INFO;
+
 uint32
 field_length_from_packed(enum_field_types field_type, byte const *data);
 
@@ -128,6 +131,7 @@ private:
 struct RPL_TABLE_LIST
   : public st_table_list
 {
+  bool m_tabledef_valid;
   table_def m_tabledef;
 };