Revert "SQL: Backup_query_start_time RAII"

This reverts commit 07b1a774.

sql/sp_head.cc

@@ -3272,7 +3272,7 @@ sp_instr_stmt::execute(THD *thd, uint *nextp)
   int res;
   bool save_enable_slow_log;
   const CSET_STRING query_backup= thd->query_string;
-  Backup_query_start_time time_info;
+  QUERY_START_TIME_INFO time_info;
   Sub_statement_state backup_state;
   DBUG_ENTER("sp_instr_stmt::execute");
   DBUG_PRINT("info", ("command: %d", m_lex_keeper.sql_command()));
@@ -3288,7 +3288,7 @@ sp_instr_stmt::execute(THD *thd, uint *nextp)
       Save start time info for the CALL statement and overwrite it with the
       current time for log_slow_statement() to log the individual query timing.
     */
-    time_info.backup(*thd);
+    thd->backup_query_start_time(&time_info);
     thd->set_time();
   }
   thd->store_slow_query_state(&backup_state);
@@ -3354,6 +3354,9 @@ sp_instr_stmt::execute(THD *thd, uint *nextp)
       thd->get_stmt_da()->reset_diagnostics_area();
     }
   }
+  /* Restore the original query start time */
+  if (thd->enable_slow_log)
+    thd->restore_query_start_time(&time_info);
 
   DBUG_RETURN(res || thd->is_error());
 }

sql/sql_class.h

@@ -2089,36 +2089,14 @@ struct QUERY_START_TIME_INFO
   my_time_t start_time;
   ulong     start_time_sec_part;
   ulonglong start_utime, utime_after_lock;
-};
-
-class Backup_query_start_time : public QUERY_START_TIME_INFO
-{
-  QUERY_START_TIME_INFO *m_origin;
 
-public:
-  Backup_query_start_time() : m_origin(NULL)
-  {}
-  Backup_query_start_time(QUERY_START_TIME_INFO &origin)
+  void backup_query_start_time(QUERY_START_TIME_INFO *backup)
   {
-    backup(origin);
+    *backup= *this;
   }
-  ~Backup_query_start_time()
+  void restore_query_start_time(QUERY_START_TIME_INFO *backup)
   {
-    restore();
-  }
-  void backup(QUERY_START_TIME_INFO &origin)
-  {
-    m_origin= &origin;
-    QUERY_START_TIME_INFO *backup_= this;
-    *backup_= origin;
-  }
-  void restore()
-  {
-    if (m_origin)
-    {
-      *m_origin= *this;
-      m_origin= NULL;
-    }
+    *this= *backup;
   }
 };