MDEV-26820 Added vcol info in temp field.

mysql-test/suite/vcol/r/vcol_misc.result

@@ -591,3 +591,21 @@ DROP TABLE t;
 #
 # End of 10.5 tests
 #
+#
+# MDEV-26820 Assertion `marked_for_read()' failed upon SELECT with VALUE(virtual column)
+#
+CREATE TABLE t1 (a VARCHAR(8), b VARCHAR(8) AS (REPEAT(a,1)) VIRTUAL) ENGINE=MyISAM;
+INSERT INTO t1 (a) VALUES ('foo'),('bar');
+SELECT VALUE(b) FROM (SELECT * FROM t1) sq;
+VALUE(b)
+NULL
+NULL
+DROP TABLE t1;
+CREATE TABLE t1 ( id uuid, vid varchar(255) GENERATED always AS (id)) engine=aria;
+INSERT INTO t1 (id) values (uuid()),(uuid()),(uuid());
+SELECT VALUE( vid ) FROM (select * from t1)dt;
+VALUE( vid )
+NULL
+NULL
+NULL
+DROP TABLE t1;

mysql-test/suite/vcol/t/vcol_misc.test

@@ -560,3 +560,19 @@ DROP TABLE t;
 --echo #
 --echo # End of 10.5 tests
 --echo #
+
+--echo #
+--echo # MDEV-26820 Assertion `marked_for_read()' failed upon SELECT with VALUE(virtual column)
+--echo #
+
+CREATE TABLE t1 (a VARCHAR(8), b VARCHAR(8) AS (REPEAT(a,1)) VIRTUAL) ENGINE=MyISAM;
+INSERT INTO t1 (a) VALUES ('foo'),('bar');
+SELECT VALUE(b) FROM (SELECT * FROM t1) sq;
+
+DROP TABLE t1;
+
+CREATE TABLE t1 ( id uuid, vid varchar(255) GENERATED always AS (id)) engine=aria;
+INSERT INTO t1 (id) values (uuid()),(uuid()),(uuid());
+SELECT VALUE( vid ) FROM (select * from t1)dt;
+
+DROP TABLE t1;

sql/item.cc

@@ -10232,6 +10232,7 @@ bool Item_insert_value::fix_fields(THD *thd, Item **items)
       set_field(tmp_field);
       // the index is important when read bits set
       tmp_field->field_index= field_arg->field->field_index;
+      tmp_field->vcol_info= field_arg->field->vcol_info;
     }
   }
   return FALSE;