MDEV-30615 Can't read from I_S.INNODB_SYS_INDEXES when having a discarded tablesace

- MY_I_S_MAYBE_NULL field attributes is added PAGE_NO and SPACE in
innodb_sys_index table. By doing this, InnoDB can set null for these
fields when it encounters discarded tablespace

mysql-test/suite/innodb/r/full_crc32_import.result

@@ -173,6 +173,17 @@ UNLOCK TABLES;
 SET GLOBAL innodb_compression_algorithm=0;
 ALTER TABLE t1 FORCE;
 ALTER TABLE t1 DISCARD TABLESPACE;
+# Display the discarded table name by using SPACE and PAGE_NO
+# column in INNODB_SYS_INDEXES and discard doesn't affect the
+# SPACE in INNODB_SYS_TABLES
+SELECT t.NAME, t.SPACE BETWEEN 1 and 0xFFFFFFEF as SYS_TABLE_SPACE_RANGE
+FROM INFORMATION_SCHEMA.INNODB_SYS_TABLES t
+WHERE t.TABLE_ID IN (
+SELECT i.TABLE_ID FROM
+INFORMATION_SCHEMA.INNODB_SYS_INDEXES i WHERE
+i.PAGE_NO IS NULL and i.SPACE IS NULL);
+NAME	SYS_TABLE_SPACE_RANGE
+test/t1	1
 db.opt
 t1.frm
 restore: t1 .ibd and .cfg files

mysql-test/suite/innodb/t/full_crc32_import.test

@@ -195,6 +195,16 @@ SET GLOBAL innodb_compression_algorithm=0;
 ALTER TABLE t1 FORCE;
 ALTER TABLE t1 DISCARD TABLESPACE;
 
+--echo # Display the discarded table name by using SPACE and PAGE_NO
+--echo # column in INNODB_SYS_INDEXES and discard doesn't affect the
+--echo # SPACE in INNODB_SYS_TABLES
+SELECT t.NAME, t.SPACE BETWEEN 1 and 0xFFFFFFEF as SYS_TABLE_SPACE_RANGE
+FROM INFORMATION_SCHEMA.INNODB_SYS_TABLES t
+WHERE t.TABLE_ID IN (
+	SELECT i.TABLE_ID FROM
+	INFORMATION_SCHEMA.INNODB_SYS_INDEXES i WHERE
+	i.PAGE_NO IS NULL and i.SPACE IS NULL);
+
 --list_files $MYSQLD_DATADIR/test
 perl;
 do "$ENV{MTR_SUITE_DIR}/include/innodb-util.pl";

storage/innobase/handler/i_s.cc

@@ -5430,10 +5430,10 @@ static ST_FIELD_INFO innodb_sysindex_fields_info[]=
    0, 0, "", SKIP_OPEN_TABLE},
 #define SYS_INDEX_PAGE_NO	5
   {"PAGE_NO", MY_INT32_NUM_DECIMAL_DIGITS, MYSQL_TYPE_LONG,
-   0, 0, "", SKIP_OPEN_TABLE},
+   0, MY_I_S_MAYBE_NULL, "", SKIP_OPEN_TABLE},
 #define SYS_INDEX_SPACE		6
   {"SPACE", MY_INT32_NUM_DECIMAL_DIGITS, MYSQL_TYPE_LONG,
-   0, 0, "", SKIP_OPEN_TABLE},
+   0, MY_I_S_MAYBE_NULL, "", SKIP_OPEN_TABLE},
 #define SYS_INDEX_MERGE_THRESHOLD 7
   {"MERGE_THRESHOLD", MY_INT32_NUM_DECIMAL_DIGITS, MYSQL_TYPE_LONG,
    0, 0, "", SKIP_OPEN_TABLE},
@@ -5483,12 +5483,14 @@ i_s_dict_fill_sys_indexes(
 	if (index->page == FIL_NULL) {
 		fields[SYS_INDEX_PAGE_NO]->set_null();
 	} else {
+		fields[SYS_INDEX_PAGE_NO]->set_notnull();
 		OK(fields[SYS_INDEX_PAGE_NO]->store(index->page, true));
 	}
 
-	if (space_id == ULINT_UNDEFINED) {
+	if (space_id == FIL_NULL) {
 		fields[SYS_INDEX_SPACE]->set_null();
 	} else {
+		fields[SYS_INDEX_SPACE]->set_notnull();
 		OK(fields[SYS_INDEX_SPACE]->store(space_id, true));
 	}