MDEV-21497 Make Field_time, Field_datetime, Field_timestamp abstract

- Making classes Field_time, Field_datetime, Field_timestamp abstract
- Adding instantiable Field_time0, Field_datetime0, Field_timestamp0 classes
- Removing redundant cast in field_conv.cc, item_timefunc.cc, sp.cc in calls for set_time() and get_timestamp()
- Replacing store_TIME() to store_timestamp() in log.cc and removing redundant cast

1 files changed, 2 insertions, 2 deletions

diff --git a/sql/field_conv.cc b/sql/field_conv.cc
index f975597cf70..80a2ee1b06e 100644
--- a/sql/field_conv.cc
+++ b/sql/field_conv.cc
@@ -168,7 +168,7 @@ int convert_null_to_field_value_or_error(Field *field)
 {
   if (field->type() == MYSQL_TYPE_TIMESTAMP)
   {
-    ((Field_timestamp*) field)->set_time();
+    field->set_time();
     return 0;
   }
 
@@ -315,7 +315,7 @@ static void do_copy_timestamp(Copy_field *copy)
   if (*copy->from_null_ptr & copy->from_bit)
   {
     /* Same as in set_field_to_null_with_conversions() */
-    ((Field_timestamp*) copy->to_field)->set_time();
+    copy->to_field->set_time();
   }
   else
     (copy->do_copy2)(copy);