MDEV-35420 Server aborts while deleting the record in spatial index

- InnoDB spatial index keep track of all active r-tree search cursor.
While deleting a record from the index, spatial index discards the
page present in the active r-tree search cursor.
rtr_check_discard_page() have the assumption that all active
r-tree cursor should point to shadow block for the matched records.
If the cursor was opened when the table is empty then
there won't be any shadow block.

Author: Thirunarayanan

mysql-test/suite/innodb_gis/r/rollback.result

@@ -412,3 +412,24 @@ update t1 set a=point(5,5), b=point(5,5), c=5 where i < 3;
 ERROR HY000: Lost connection to server during query
 insert into t1 values(5, point(5,5), point(5,5), 5);
 drop table t1;
+#
+# MDEV-35420 Server aborts while deleting the record
+#               in spatial index
+#
+CREATE TABLE t1 (c POINT NOT NULL, SPATIAL(c)) engine=InnoDB;
+CHECK TABLE t1;
+Table	Op	Msg_type	Msg_text
+test.t1	check	status	OK
+INSERT INTO t1  VALUES(ST_GeomFromText('POINT(114368751 656950466)'));
+BEGIN;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+ROLLBACK;
+DROP TABLE t1;

mysql-test/suite/innodb_gis/t/rollback.test

@@ -475,3 +475,23 @@ update t1 set a=point(5,5), b=point(5,5), c=5 where i < 3;
 insert into t1 values(5, point(5,5), point(5,5), 5);
 
 drop table t1;
+
+--echo #
+--echo # MDEV-35420 Server aborts while deleting the record
+--echo #               in spatial index
+--echo #
+CREATE TABLE t1 (c POINT NOT NULL, SPATIAL(c)) engine=InnoDB;
+CHECK TABLE t1;
+INSERT INTO t1  VALUES(ST_GeomFromText('POINT(114368751 656950466)'));
+BEGIN;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+INSERT INTO t1 SELECT * FROM t1;
+ROLLBACK;
+DROP TABLE t1;

storage/innobase/gis/gis0sea.cc

@@ -1565,7 +1565,8 @@ rtr_check_discard_page(
 		if (auto matches = rtr_info->matches) {
 			mysql_mutex_lock(&matches->rtr_match_mutex);
 
-			if (matches->block->page.id() == id) {
+			if (matches->block &&
+			    matches->block->page.id() == id) {
 				matches->matched_recs->clear();
 				matches->valid = false;
 			}