MDEV-4292 fix.

Fixed printing column_get finction.

mysql-test/t/dyncol.test

@@ -546,3 +546,60 @@ select hex(COLUMN_CREATE(0, COLUMN_GET(@a, 9 AS DECIMAL(19,0))));
 
 select hex(COLUMN_CREATE(0, COLUMN_GET(COLUMN_CREATE(0, 0.0 as decimal), 0 as decimal)));
 select hex(COLUMN_CREATE(0, 0.0 as decimal));
+
+--echo #
+--echo # MDEV-4292: parse error when selecting on views using dynamic column
+--echo #
+create table t1 (i int, d blob);
+
+create view v1 as select i, column_get(d, 1 as binary) as a from t1;
+select * from v1;
+show create view v1;
+drop view v1;
+
+create view v1 as select i, column_get(d, 1 as int) as a from t1;
+select * from v1;
+show create view v1;
+drop view v1;
+
+create view v1 as select i, column_get(d, 1 as unsigned int) as a from t1;
+select * from v1;
+show create view v1;
+drop view v1;
+
+create view v1 as select i, column_get(d, 1 as date) as a from t1;
+select * from v1;
+show create view v1;
+drop view v1;
+
+create view v1 as select i, column_get(d, 1 as time) as a from t1;
+select * from v1;
+show create view v1;
+drop view v1;
+
+create view v1 as select i, column_get(d, 1 as datetime) as a from t1;
+select * from v1;
+show create view v1;
+drop view v1;
+
+create view v1 as select i, column_get(d, 1 as decimal) as a from t1;
+select * from v1;
+show create view v1;
+drop view v1;
+
+create view v1 as select i, column_get(d, 1 as double) as a from t1;
+select * from v1;
+show create view v1;
+drop view v1;
+
+create view v1 as select i, column_get(d, 1 as char) as a from t1;
+select * from v1;
+show create view v1;
+drop view v1;
+
+drop table t1;
+
+--echo #
+--echo # end of 5.3 tests
+--echo #
+

sql/item_strfunc.cc

@@ -4246,11 +4246,16 @@ bool Item_dyncol_get::get_date(MYSQL_TIME *ltime, uint fuzzy_date)
 
 void Item_dyncol_get::print(String *str, enum_query_type query_type)
 {
+  /* see create_func_dyncol_get */
+  DBUG_ASSERT(str->length() >= 5);
+  DBUG_ASSERT(strncmp(str->ptr() + str->length() - 5, "cast(", 5) == 0);
+
+  str->length(str->length() - 5);    // removing "cast("
   str->append(STRING_WITH_LEN("column_get("));
   args[0]->print(str, query_type);
   str->append(',');
   args[1]->print(str, query_type);
-  str->append(')');
+  /* let the parent cast item add " as <type>)" */
 }