Bug#57058: SERVER_QUERY_WAS_SLOW not wired up.

Finalize the server flags after any kind of command is executed.
To avoid updating the flag multiple times, reorganize code so that
its invoked only once for each command.

sql/log_event.cc:
  Explicit update after the query is executed in the slave.
sql/sql_parse.cc:
  Reorganize so that the status flag is updated for any command and
  not done twice for a query command.

sql/log_event.cc

@@ -3353,6 +3353,8 @@ int Query_log_event::do_apply_event(Relay_log_info const *rli,
       if (!parser_state.init(thd, thd->query(), thd->query_length()))
       {
         mysql_parse(thd, thd->query(), thd->query_length(), &parser_state);
+        /* Finalize server status flags after executing a statement. */
+        thd->update_server_status();
         log_slow_statement(thd);
       }
 

sql/sql_parse.cc

@@ -1034,11 +1034,13 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
     while (!thd->killed && (parser_state.m_lip.found_semicolon != NULL) &&
            ! thd->is_error())
     {
-      char *beginning_of_next_stmt= (char*)
-        parser_state.m_lip.found_semicolon;
       /*
         Multiple queries exits, execute them individually
       */
+      char *beginning_of_next_stmt= (char*) parser_state.m_lip.found_semicolon;
+
+      /* Finalize server status flags after executing a statement. */
+      thd->update_server_status();
       thd->protocol->end_statement();
       query_cache_end_of_result(thd);
       ulong length= (ulong)(packet_end - beginning_of_next_stmt);
@@ -1384,6 +1386,8 @@ bool dispatch_command(enum enum_server_command command, THD *thd,
               (thd->open_tables == NULL ||
                (thd->locked_tables_mode == LTM_LOCK_TABLES)));
 
+  /* Finalize server status flags after executing a command. */
+  thd->update_server_status();
   thd->protocol->end_statement();
   query_cache_end_of_result(thd);
 
@@ -5504,8 +5508,6 @@ void mysql_parse(THD *thd, char *rawbuf, uint length,
     thd->end_statement();
     thd->cleanup_after_query();
     DBUG_ASSERT(thd->change_list.is_empty());
-    /* Finalize server status flags after executing a statement. */
-    thd->update_server_status();
   }
 
   DBUG_VOID_RETURN;