don't set default value in temp table if NO_DEFAULT_VALUE_FLAG

when an internal temporary table field is created from a real field,
a new temp field should only copy a default from the source field
when the latter has it

mysql-test/main/default.result

@@ -3463,5 +3463,26 @@ SELECT 1 FROM t1 GROUP BY DEFAULT(pk);
 1
 DROP TABLE t1;
 #
+# MDEV-29890 Update with inner join false row count result
+#
+create table t1 (a int not null);
+select column_name, column_default, column_default is not null as 'has_default', is_nullable from information_schema.columns where table_schema='test' and table_name='t1';
+column_name	column_default	has_default	is_nullable
+a	NULL	0	NO
+create or replace view v1 as select * from t1;
+select column_name, column_default, column_default is not null as 'has_default', is_nullable from information_schema.columns where table_schema='test' and table_name='v1';
+column_name	column_default	has_default	is_nullable
+a	NULL	0	NO
+create or replace view v1 as select * from t1 group by a;
+select column_name, column_default, column_default is not null as 'has_default', is_nullable from information_schema.columns where table_schema='test' and table_name='v1';
+column_name	column_default	has_default	is_nullable
+a	NULL	0	NO
+create or replace view v1 as select * from t1 group by a with rollup;
+select column_name, column_default, column_default is not null as 'has_default', is_nullable from information_schema.columns where table_schema='test' and table_name='v1';
+column_name	column_default	has_default	is_nullable
+a	NULL	1	YES
+drop view v1;
+drop table t1;
+#
 # End of 10.4 test
 #

mysql-test/main/default.test

@@ -2169,6 +2169,20 @@ INSERT INTO t1 VALUES (),();
 SELECT 1 FROM t1 GROUP BY DEFAULT(pk);
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-29890 Update with inner join false row count result
+--echo #
+create table t1 (a int not null);
+select column_name, column_default, column_default is not null as 'has_default', is_nullable from information_schema.columns where table_schema='test' and table_name='t1';
+create or replace view v1 as select * from t1;
+select column_name, column_default, column_default is not null as 'has_default', is_nullable from information_schema.columns where table_schema='test' and table_name='v1';
+create or replace view v1 as select * from t1 group by a;
+select column_name, column_default, column_default is not null as 'has_default', is_nullable from information_schema.columns where table_schema='test' and table_name='v1';
+create or replace view v1 as select * from t1 group by a with rollup;
+select column_name, column_default, column_default is not null as 'has_default', is_nullable from information_schema.columns where table_schema='test' and table_name='v1';
+drop view v1;
+drop table t1;
+
 --echo #
 --echo # End of 10.4 test
 --echo #

mysql-test/main/olap.result

@@ -695,7 +695,7 @@ CREATE VIEW v1 AS
 SELECT a, LENGTH(a), COUNT(*) FROM t1 GROUP BY a WITH ROLLUP;
 DESC v1;
 Field	Type	Null	Key	Default	Extra
-a	int(11)	YES		0	
+a	int(11)	YES		NULL	
 LENGTH(a)	int(10)	YES		NULL	
 COUNT(*)	bigint(21)	NO		0	
 SELECT * FROM v1;
@@ -858,7 +858,7 @@ INSERT INTO t1 VALUES (1),(2);
 CREATE OR REPLACE VIEW v1 AS SELECT a, LENGTH(a), COUNT(*) FROM t1 GROUP BY a WITH ROLLUP;
 DESCRIBE v1;
 Field	Type	Null	Key	Default	Extra
-a	int(11)	YES		0	
+a	int(11)	YES		NULL	
 LENGTH(a)	int(10)	YES		NULL	
 COUNT(*)	bigint(21)	NO		0	
 DROP VIEW v1;
@@ -868,7 +868,7 @@ INSERT INTO t1 VALUES (1),(2);
 CREATE OR REPLACE VIEW v1 AS SELECT a, LENGTH(a), COUNT(*) FROM t1 GROUP BY a WITH ROLLUP;
 DESCRIBE v1;
 Field	Type	Null	Key	Default	Extra
-a	bigint(20)	YES		0	
+a	bigint(20)	YES		NULL	
 LENGTH(a)	int(10)	YES		NULL	
 COUNT(*)	bigint(21)	NO		0	
 DROP VIEW v1;
@@ -893,8 +893,8 @@ DROP VIEW v1;
 CREATE VIEW v1 AS SELECT a, b FROM t1 GROUP BY a,b WITH ROLLUP;
 DESC v1;
 Field	Type	Null	Key	Default	Extra
-a	int(11)	YES		0	
-b	int(20)	YES		0	
+a	int(11)	YES		NULL	
+b	int(20)	YES		NULL	
 DROP VIEW v1;
 DROP TABLE t1;
 #

sql/sql_select.cc

@@ -18241,7 +18241,8 @@ Field *Item_field::create_tmp_field_ex(TABLE *table,
   src->set_field(field);
   if (!(result= create_tmp_field_from_item_field(table, NULL, param)))
     return NULL;
-  if (field->eq_def(result))
+  if (!(field->flags & NO_DEFAULT_VALUE_FLAG) &&
+      field->eq_def(result))
     src->set_default_field(field);
   return result;
 }