fix for Valgrind errors: query_id needs to be inited early (already fixed in...

fix for Valgrind errors: query_id needs to be inited early (already fixed in 5.0 by Konstantin) and so does client_capabilities (not fixed in 5.0);
because they are used by net_printf() and push_warning(), which can be called if check_connection() fails.

sql/mysqld.cc

@@ -3460,7 +3460,6 @@ static int bootstrap(FILE *file)
 
   THD *thd= new THD;
   thd->bootstrap=1;
-  thd->client_capabilities=0;
   my_net_init(&thd->net,(st_vio*) 0);
   thd->max_client_packet_length= thd->net.max_packet;
   thd->master_access= ~(ulong)0;

sql/repl_failsafe.cc

@@ -67,7 +67,6 @@ static int init_failsafe_rpl_thread(THD* thd)
   */
   thd->system_thread = thd->bootstrap = 1;
   thd->host_or_ip= "";
-  thd->client_capabilities = 0;
   my_net_init(&thd->net, 0);
   thd->net.read_timeout = slave_net_timeout;
   thd->max_client_packet_length=thd->net.max_packet;

sql/slave.cc

@@ -2617,7 +2617,6 @@ static int init_slave_thread(THD* thd, SLAVE_THD_TYPE thd_type)
   thd->system_thread = (thd_type == SLAVE_THD_SQL) ?
     SYSTEM_THREAD_SLAVE_SQL : SYSTEM_THREAD_SLAVE_IO; 
   thd->host_or_ip= "";
-  thd->client_capabilities = 0;
   my_net_init(&thd->net, 0);
   thd->net.read_timeout = slave_net_timeout;
   thd->master_access= ~(ulong)0;

sql/sql_class.cc

@@ -186,6 +186,7 @@ THD::THD()
   variables.pseudo_thread_id= 0;
   one_shot_set= 0;
   file_id = 0;
+  query_id= 0;
   warn_id= 0;
   db_charset= global_system_variables.collation_database;
   mysys_var=0;
@@ -196,6 +197,7 @@ THD::THD()
   net.vio=0;
 #endif
   net.last_error[0]=0;				// If error on boot
+  client_capabilities= 0;                       // minimalistic client
   ull=0;
   system_thread=cleanup_done=0;
   peer_port= 0;					// For SHOW PROCESSLIST