btr_cur_instant_init_low(): Always initialize index->n_core_fields

mysql-test/suite/innodb/r/instant_drop.result

@@ -151,45 +151,6 @@ f3	f6
 drop table t1;
 create table t1(f1 int, f2 int not null) engine=innodb;
 insert into t1(f1, f2) values(1, 2);
-select * from information_schema.innodb_sys_columns;
-TABLE_ID	NAME	POS	MTYPE	PRTYPE	LEN
-11	ID	0	1	524292	0
-11	FOR_NAME	1	1	524292	0
-11	REF_NAME	2	1	524292	0
-11	N_COLS	3	6	0	4
-12	ID	0	1	524292	0
-12	POS	1	6	0	4
-12	FOR_COL_NAME	2	1	524292	0
-12	REF_COL_NAME	3	1	524292	0
-13	SPACE	0	6	0	4
-13	NAME	1	1	524292	0
-13	FLAGS	2	6	0	4
-14	SPACE	0	6	0	4
-14	PATH	1	1	524292	0
-15	TABLE_ID	0	6	0	8
-15	POS	1	6	0	4
-15	BASE_POS	2	6	0	4
-16	database_name	0	12	5439759	192
-16	table_name	1	12	5439759	192
-16	last_update	2	3	526087	4
-16	n_rows	3	6	1800	8
-16	clustered_index_size	4	6	1800	8
-16	sum_of_other_index_sizes	5	6	1800	8
-17	database_name	0	12	5439759	192
-17	table_name	1	12	5439759	192
-17	index_name	2	12	5439759	192
-17	last_update	3	3	526087	4
-17	stat_name	4	12	5439759	192
-17	stat_value	5	6	1800	8
-17	sample_size	6	6	1544	8
-17	stat_description	7	12	5443855	3072
-18	transaction_id	0	6	1800	8
-18	commit_id	1	6	1800	8
-18	begin_timestamp	2	3	526087	7
-18	commit_timestamp	3	3	526087	7
-18	isolation_level	4	6	1022	1
-26	f1	0	6	1027	4
-26	f2	1	6	1283	4
 alter table t1 drop column f2, add column f4 varchar(100) default repeat('a', 20), add column f5 int default 10,  algorithm=instant;
 select * from t1;
 f1	f4	f5

mysql-test/suite/innodb/t/instant_drop.test

@@ -76,7 +76,6 @@ drop table t1;
 
 create table t1(f1 int, f2 int not null) engine=innodb;
 insert into t1(f1, f2) values(1, 2);
-select * from information_schema.innodb_sys_columns;
 alter table t1 drop column f2, add column f4 varchar(100) default repeat('a', 20), add column f5 int default 10,  algorithm=instant;
 select * from t1;
 show create table t1;

storage/innobase/btr/btr0cur.cc

@@ -392,9 +392,7 @@ when loading a table definition.
 @return	error code
 @retval	DB_SUCCESS	if no error occurred
 @retval	DB_CORRUPTION	if any corruption was noticed */
-static
-dberr_t
-btr_cur_instant_init_low(dict_index_t* index, mtr_t* mtr)
+static dberr_t btr_cur_instant_init_low(dict_index_t* index, mtr_t* mtr)
 {
 	ut_ad(index->is_primary());
 	ut_ad(index->n_core_null_bytes == dict_index_t::NO_CORE_NULL_BYTES);
@@ -655,6 +653,11 @@ btr_cur_instant_root_init(dict_index_t* index, const page_t* page)
 		return true;
 	}
 
+	if (n > REC_MAX_N_FIELDS) {
+		return true;
+	}
+
+	index->n_core_fields = n;
 	const rec_t* infimum = page_get_infimum_rec(page);
 	const rec_t* supremum = page_get_supremum_rec(page);
 
@@ -667,7 +670,6 @@ btr_cur_instant_root_init(dict_index_t* index, const page_t* page)
 			return true;
 		}
 
-		index->n_core_fields = n;
 		ut_ad(!index->is_dummy);
 		ut_d(index->is_dummy = true);
 		index->n_core_null_bytes = UT_BITS_IN_BYTES(

storage/innobase/dict/dict0mem.cc

@@ -1583,7 +1583,7 @@ bool dict_table_t::deserialise_columns(const byte* metadata, ulint len)
 	unsigned num_non_pk_fields = mach_read_from_4(metadata);
 	metadata += 4;
 
-	if (num_non_pk_fields >= REC_MAX_N_FIELDS) {
+	if (num_non_pk_fields >= REC_MAX_N_FIELDS - 3) {
 		return true;
 	}