MDEV-29021 mark fields that have explicit values

so that table->update_default_fields() would know what to update

mysql-test/suite/rpl/include/rpl_extra_col_slave.test

@@ -397,8 +397,7 @@ sync_slave_with_master;
   STOP SLAVE;
   --source include/reset_slave.inc
   eval CREATE TABLE t9 (a INT KEY, b BLOB, c CHAR(5),
-                        d TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP 
-                          ON UPDATE CURRENT_TIMESTAMP,
+                        d TIMESTAMP NOT NULL DEFAULT 0,
                         e INT NOT NULL,
                         f text not null,
                         g text,

mysql-test/suite/rpl/r/rpl_extra_col_slave_innodb.result

@@ -260,8 +260,7 @@ connection slave;
 STOP SLAVE;
 include/reset_slave.inc
 CREATE TABLE t9 (a INT KEY, b BLOB, c CHAR(5),
-d TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP 
-ON UPDATE CURRENT_TIMESTAMP,
+d TIMESTAMP NOT NULL DEFAULT 0,
 e INT NOT NULL,
 f text not null,
 g text,

mysql-test/suite/rpl/r/rpl_extra_col_slave_myisam.result

@@ -260,8 +260,7 @@ connection slave;
 STOP SLAVE;
 include/reset_slave.inc
 CREATE TABLE t9 (a INT KEY, b BLOB, c CHAR(5),
-d TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP 
-ON UPDATE CURRENT_TIMESTAMP,
+d TIMESTAMP NOT NULL DEFAULT 0,
 e INT NOT NULL,
 f text not null,
 g text,

sql/rpl_record.cc

@@ -265,6 +265,7 @@ int unpack_row(rpl_group_info *rgi, TABLE *table, uint const colcnt,
      */
     if (bitmap_is_set(cols, (uint)(field_ptr -  begin_ptr)))
     {
+      (*field_ptr)->set_has_explicit_value();
       if ((null_mask & 0xFF) == 0)
       {
         DBUG_ASSERT(null_ptr < row_data + master_null_byte_count);