MDEV-15348 Failure to load CREATE SEQUENCE...ROW_FORMAT=REDUNDANT

dict_sys_tables_type_valid(): Do not reject NO_ROLLBACK (sequence)
in ROW_FORMAT=REDUNDANT.

dict_load_table_low(): When flagging an error, assign *table = NULL.
Failure to do so could cause a crash if an error was flagged when
accessing INFORMATION_SCHEMA.INNODB_SYS_TABLES.

mysql-test/suite/sql_sequence/create.result

@@ -638,6 +638,9 @@ drop table s;
 # MDEV-15115 Assertion failure in CREATE SEQUENCE...ROW_FORMAT=REDUNDANT
 #
 CREATE SEQUENCE seq1 ENGINE=InnoDB ROW_FORMAT=REDUNDANT;
+SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_TABLES WHERE NAME='test/seq1';
+TABLE_ID	NAME	FLAG	N_COLS	SPACE	ROW_FORMAT	ZIP_PAGE_SIZE	SPACE_TYPE
+#	test/seq1	12288	11	#	Redundant	0	Single
 DROP SEQUENCE seq1;
 CREATE TEMPORARY SEQUENCE seq1 ENGINE=InnoDB ROW_FORMAT=REDUNDANT;
 DROP TEMPORARY SEQUENCE seq1;

mysql-test/suite/sql_sequence/create.test

@@ -455,6 +455,10 @@ drop table s;
 --echo # MDEV-15115 Assertion failure in CREATE SEQUENCE...ROW_FORMAT=REDUNDANT
 --echo #
 CREATE SEQUENCE seq1 ENGINE=InnoDB ROW_FORMAT=REDUNDANT;
+
+--replace_column 1 # 5 #
+SELECT * FROM INFORMATION_SCHEMA.INNODB_SYS_TABLES WHERE NAME='test/seq1';
+
 DROP SEQUENCE seq1;
 CREATE TEMPORARY SEQUENCE seq1 ENGINE=InnoDB ROW_FORMAT=REDUNDANT;
 DROP TEMPORARY SEQUENCE seq1;

storage/innobase/dict/dict0load.cc

@@ -1136,8 +1136,9 @@ dict_sys_tables_type_valid(ulint type, bool not_redundant)
 	}
 
 	if (!not_redundant) {
-		/* SYS_TABLES.TYPE must be 1 for ROW_FORMAT=REDUNDANT. */
-		return(false);
+		/* SYS_TABLES.TYPE must be 1 or 1|DICT_TF_MASK_NO_ROLLBACK
+		for ROW_FORMAT=REDUNDANT. */
+		return !(type & ~(1 | DICT_TF_MASK_NO_ROLLBACK));
 	}
 
 	if (type >= 1U << DICT_TF_POS_UNUSED) {
@@ -2637,11 +2638,13 @@ dict_load_table_low(table_name_t& name, const rec_t* rec, dict_table_t** table)
 	ulint		n_v_col;
 
 	if (const char* error_text = dict_sys_tables_rec_check(rec)) {
+		*table = NULL;
 		return(error_text);
 	}
 
 	if (!dict_sys_tables_rec_read(rec, name, &table_id, &space_id,
 				      &t_num, &flags, &flags2)) {
+		*table = NULL;
 		return(dict_load_table_flags);
 	}