MDEV-26546 SIGSEGV's in spider_db_connect on SHOW TABLE and spider_db… …_mbase::connect (and SIGSEGV's in check_vcol_forward_refs and inline_mysql_mutex_lock)

Not the SPIDER issue - happens to INSERT DELAYED.
the field::make_new_field does't copy the LONG_UNIQUE_HASH_FIELD
flag to the new field. Though the Delayed_insert::get_local_table
copies the field->vcol_info for this field. Ad a result
the parse_vcol_defs doesn't create the expression for that column
so the field->vcol_info->expr is NULL. Which leads to crash.
Backported fix for this from 10.5 - the flagg added in the
Delayed_insert::get_local_table.

Another problem with the USING HASH key is thst the
parse_vcol_defs modifies the table->keys content. Then the same
parse_vcol_defs is called on the table copy that has keys already
modified. Backported fix for that from 10.5 - key copying added
tot the Delayed_insert::get_local_table.

Finally - the created copy has to clear the expr_arena as
this table is not in the thd->open_tables list so won't be
cleared automatically.

1 files changed, 12 insertions, 0 deletions

diff --git a/mysql-test/main/delayed.test b/mysql-test/main/delayed.test
index 573985fec1f..428a3d4c4b0 100644
--- a/mysql-test/main/delayed.test
+++ b/mysql-test/main/delayed.test
@@ -642,3 +642,15 @@ insert delayed into t1 values (3,3);
 flush tables t1;
 select * from t1;
 drop table t1;
+
+--echo #
+--echo # MDEV-26546 SIGSEGV's in spider_db_connect on SHOW TABLE and
+--echo # spider_db_mbase::connect (and SIGSEGV's in check_vcol_forward_refs
+--echo # and inline_mysql_mutex_lock)
+--echo #
+
+CREATE TABLE t1 (c0 INT,UNIQUE (c0) USING HASH) ENGINE=MYISAM;
+INSERT DELAYED INTO t1 VALUES (0);
+INSERT DELAYED INTO t1 VALUES (0);
+DROP TABLE t1;
+