Bug #28430 Failure in replication of innodb partitioned tables on row/mixed format.

In the ha_partition::position() we didn't calculate the number
of the partition of the record. We used m_last_part value instead,
relying on that it is set in other place like previous call of a method
like ::write_row(). In replication we don't call any of these befor
position(). Delete_rows_log_event::do_exec_row calls find_and_fetch_row.
In case of InnoDB-based PARTITION table, we have HA_PRIMARY_KEY_REQUIRED_FOR_POSITION
enabled, so use position() / rnd_pos() calls to fetch the record.

Fixed by adding partition_id calculation to the ha_partition::position()

mysql-test/r/partition_pruning.result

@@ -631,7 +631,7 @@ flush status;
 delete from t2 where b > 5;
 show status like 'Handler_read_rnd_next';
 Variable_name	Value
-Handler_read_rnd_next	1215
+Handler_read_rnd_next	1115
 show status like 'Handler_read_key';
 Variable_name	Value
 Handler_read_key	0
@@ -645,7 +645,7 @@ flush status;
 delete from t2 where b < 5 or b > 3;
 show status like 'Handler_read_rnd_next';
 Variable_name	Value
-Handler_read_rnd_next	1215
+Handler_read_rnd_next	1115
 show status like 'Handler_read_key';
 Variable_name	Value
 Handler_read_key	0

sql/ha_partition.cc

@@ -3235,9 +3235,14 @@ end_dont_reset_start_part:
 
 void ha_partition::position(const uchar *record)
 {
-  handler *file= m_file[m_last_part];
+  handler *file;
   DBUG_ENTER("ha_partition::position");
 
+  if (unlikely(get_part_for_delete(record, m_rec0, m_part_info, &m_last_part)))
+    m_last_part= 0;
+
+  file= m_file[m_last_part];
+
   file->position(record);
   int2store(ref, m_last_part);
   memcpy((ref + PARTITION_BYTES_IN_POS), file->ref,
@@ -5587,6 +5592,13 @@ int ha_partition::indexes_are_disabled(void)
 }
 
 
+void ha_partition::column_bitmaps_signal()
+{
+    handler::column_bitmaps_signal();
+    bitmap_union(table->read_set, &m_part_info->full_part_field_set);
+}
+
+
 /****************************************************************************
                 MODULE Partition Share
 ****************************************************************************/

sql/ha_partition.h

@@ -449,6 +449,7 @@ private:
   int handle_ordered_next(uchar * buf, bool next_same);
   int handle_ordered_prev(uchar * buf);
   void return_top_record(uchar * buf);
+  void column_bitmaps_signal();
 public:
   /*
     -------------------------------------------------------------------------