MDEV-18300: ASAN error in Field_blob::get_key_image upon UPDATE with …

…subquery

For single table updates and multi-table updates , engine independent statistics were not being
read even if the statistics were collected.
Fixed it, so when the optimizer_use_condition_selectivity > 2 then we would read the available
statistics for update queries.

mysql-test/r/update_innodb.result

@@ -65,3 +65,27 @@ SELECT * FROM t1;
 a_id	b_id	c_id
 1	NULL	NULL
 drop table t1,t2;
+#
+# MDEV-18300: ASAN error in Field_blob::get_key_image upon UPDATE with subquery
+#
+set @save_optimizer_use_condition_selectivity= @@optimizer_use_condition_selectivity;
+set @save_use_stat_tables= @@use_stat_tables;
+set use_stat_tables=preferably;
+set optimizer_use_condition_selectivity=4;
+CREATE TABLE t1 (a INT, b CHAR(8)) ENGINE=InnoDB;
+insert into t1 values (1,'foo'),(2, 'abc');
+CREATE TABLE t2 (c CHAR(8), d BLOB) ENGINE=InnoDB;
+insert into t2 values ('abc', 'foo'),('edf', 'food');
+ANALYZE TABLE t1,t2;
+UPDATE t1 SET a = 1 WHERE b = ( SELECT c FROM t2 WHERE d = 'foo' );
+SELECT * FROM t1;
+a	b
+1	foo
+1	abc
+DROP TABLE t1, t2;
+create table t1 (a int not null, b int, c int) engine=InnoDB;
+create table t2 (d int, e int) engine=InnoDB;
+update t1, t2 set a=NULL, b=2, c=NULL where b=d and e=200;
+drop table t1,t2;
+set @@optimizer_use_condition_selectivity= @save_optimizer_use_condition_selectivity;
+set @@use_stat_tables= @save_use_stat_tables;

mysql-test/t/update_innodb.test

@@ -75,3 +75,32 @@ SELECT t2.b_id FROM t1,t2 WHERE t2.c_id = t1.c_id;
 UPDATE t1 SET b_id = (SELECT t2.b_id FROM t2 t2 WHERE t2.c_id = t1.c_id);
 SELECT * FROM t1;
 drop table t1,t2;
+
+--echo #
+--echo # MDEV-18300: ASAN error in Field_blob::get_key_image upon UPDATE with subquery
+--echo #
+
+set @save_optimizer_use_condition_selectivity= @@optimizer_use_condition_selectivity;
+set @save_use_stat_tables= @@use_stat_tables;
+set use_stat_tables=preferably;
+set optimizer_use_condition_selectivity=4;
+
+CREATE TABLE t1 (a INT, b CHAR(8)) ENGINE=InnoDB;
+insert into t1 values (1,'foo'),(2, 'abc');
+CREATE TABLE t2 (c CHAR(8), d BLOB) ENGINE=InnoDB;
+insert into t2 values ('abc', 'foo'),('edf', 'food');
+
+--disable_result_log
+ANALYZE TABLE t1,t2;
+--enable_result_log
+UPDATE t1 SET a = 1 WHERE b = ( SELECT c FROM t2 WHERE d = 'foo' );
+SELECT * FROM t1;
+DROP TABLE t1, t2;
+
+create table t1 (a int not null, b int, c int) engine=InnoDB;
+create table t2 (d int, e int) engine=InnoDB;
+update t1, t2 set a=NULL, b=2, c=NULL where b=d and e=200;
+drop table t1,t2;
+
+set @@optimizer_use_condition_selectivity= @save_optimizer_use_condition_selectivity;
+set @@use_stat_tables= @save_use_stat_tables;

sql/sql_statistics.cc

@@ -4071,6 +4071,7 @@ bool is_eits_usable(Field *field)
          partition list of a table. We assume the selecticivity for
          such columns would be handled during partition pruning.
   */
+  DBUG_ASSERT(field->table->stats_is_read);
   Column_statistics* col_stats= field->read_stats;
   return col_stats && !col_stats->no_stat_values_provided() &&        //(1)
     field->type() != MYSQL_TYPE_GEOMETRY &&                           //(2)

sql/sql_update.cc

@@ -301,6 +301,8 @@ int mysql_update(THD *thd,
   if (lock_tables(thd, table_list, table_count, 0))
     DBUG_RETURN(1);
 
+  (void) read_statistics_for_tables_if_needed(thd, table_list);
+
   if (table_list->handle_derived(thd->lex, DT_MERGE_FOR_INSERT))
     DBUG_RETURN(1);
   if (table_list->handle_derived(thd->lex, DT_PREPARE))
@@ -1540,6 +1542,7 @@ int mysql_multi_update_prepare(THD *thd)
   {
     DBUG_RETURN(TRUE);
   }
+  (void) read_statistics_for_tables_if_needed(thd, table_list);
   /* @todo: downgrade the metadata locks here. */
 
   /*