Fix for Bug#33065: Mysql not writing general query logs after

sending SIGHUP.

There were two problems:
  - after some recent fix, the server started to crash after
    receiving SIGHUP. That happened because LEX of new THD-object
    was not properly initialized.
  - user-specified log options were ignored when logs were reopened.

The fix is to 1) initialize LEX and 2) take user-specified options
into account.

There is no test case in this CS, because our test suite does not
support sending SIGHUP to the server.


sql/mysqld.cc:
  Use proper logging after SIGHUP.
sql/sql_parse.cc:
  Initialize LEX of new THD -- it is required to avoid crash
  in SIGHUP handling.

sql/mysqld.cc

@@ -2573,8 +2573,18 @@ pthread_handler_t signal_hand(void *arg __attribute__((unused)))
 			     (TABLE_LIST*) 0, &not_used); // Flush logs
       }
       /* reenable logs after the options were reloaded */
-      logger.set_handlers(LOG_FILE, opt_slow_log ? LOG_TABLE:LOG_NONE,
-                          opt_log ? LOG_TABLE:LOG_NONE);
+      if (log_output_options & LOG_NONE)
+      {
+        logger.set_handlers(LOG_FILE,
+                            opt_slow_log ? LOG_TABLE : LOG_NONE,
+                            opt_log ? LOG_TABLE : LOG_NONE);
+      }
+      else
+      {
+        logger.set_handlers(LOG_FILE,
+                            opt_slow_log ? log_output_options : LOG_NONE,
+                            opt_log ? log_output_options : LOG_NONE);
+      }
       break;
 #ifdef USE_ONE_SIGNAL_HAND
     case THR_SERVER_ALARM:

sql/sql_parse.cc

@@ -6448,6 +6448,7 @@ bool reload_acl_and_cache(THD *thd, ulong options, TABLE_LIST *tables,
     {
       thd->thread_stack= (char*) &tmp_thd;
       thd->store_globals();
+      lex_start(thd);
     }
     if (thd)
     {