Fixed that sequences and default works with ps-protocol

The bug was that for prepared statments the new TABLE_LIST was
allocated in the wrong arena.

mysql-test/suite/sql_sequence/default.result

@@ -152,6 +152,22 @@ UNLOCK TABLES;
 drop table t1;
 drop sequence s1;
 #
+# Testing prepared statements
+#
+CREATE or replace SEQUENCE s1 nocache engine=myisam;
+CREATE or replace table t1 (a int default next value for s1, b int);
+PREPARE stmt FROM "insert into t1 (b) values(?)";
+execute stmt using 1;
+execute stmt using 2;
+execute stmt using 3;
+select * from t1;
+a	b
+1	1
+2	2
+3	3
+drop table t1,s1;
+deallocate prepare stmt;
+#
 # Wrong usage of default
 #
 CREATE table t1 (a int default next value for s1, b int);

mysql-test/suite/sql_sequence/default.test

@@ -90,6 +90,20 @@ UNLOCK TABLES;
 drop table t1;
 drop sequence s1;
 
+--echo #
+--echo # Testing prepared statements
+--echo #
+
+CREATE or replace SEQUENCE s1 nocache engine=myisam;
+CREATE or replace table t1 (a int default next value for s1, b int);
+PREPARE stmt FROM "insert into t1 (b) values(?)";
+execute stmt using 1;
+execute stmt using 2;
+execute stmt using 3;
+select * from t1;
+drop table t1,s1;
+deallocate prepare stmt;
+
 --echo #
 --echo # Wrong usage of default
 --echo #

sql/sql_base.cc

@@ -4243,12 +4243,33 @@ static bool table_already_fk_prelocked(TABLE_LIST *tl, LEX_CSTRING *db,
 }
 
 
+static bool internal_table_exists(TABLE_LIST *global_list,
+                                  const char *table_name)
+{
+  do
+  {
+    if (global_list->table_name == table_name)
+      return 1;
+  } while ((global_list= global_list->next_global));
+  return 0;
+}
+
+
 static bool
 add_internal_tables(THD *thd, Query_tables_list *prelocking_ctx,
-                    TABLE_LIST *global_table_list, TABLE_LIST *tables)
+                    TABLE_LIST *tables)
 {
+  TABLE_LIST *global_table_list= prelocking_ctx->query_tables;
+
   do
   {
+    /*
+      Skip table if already in the list. Can happen with prepared statements
+    */
+    if (tables->next_local &&
+        internal_table_exists(global_table_list, tables->table_name))
+      continue;
+
     TABLE_LIST *tl= (TABLE_LIST *) thd->alloc(sizeof(TABLE_LIST));
     if (!tl)
       return TRUE;
@@ -4368,12 +4389,20 @@ handle_table(THD *thd, Query_tables_list *prelocking_ctx,
   /* Open any tables used by DEFAULT (like sequence tables) */
   if (table->internal_tables &&
       ((sql_command_flags[thd->lex->sql_command] & CF_INSERTS_DATA) ||
-       thd->lex->default_used) &&
-      add_internal_tables(thd, prelocking_ctx, table_list,
-                          table->internal_tables))
-  {
-    *need_prelocking= TRUE;
-    return TRUE;
+       thd->lex->default_used))
+  {
+    Query_arena *arena, backup;
+    bool error;
+    arena= thd->activate_stmt_arena_if_needed(&backup);
+    error= add_internal_tables(thd, prelocking_ctx,
+                               table->internal_tables);
+    if (arena)
+      thd->restore_active_arena(arena, &backup);
+    if (error)
+    {
+      *need_prelocking= TRUE;
+      return TRUE;
+    }
   }
   return FALSE;
 }