MDEV-31678: UPDATE_ROWS_EVENT not setting updating columns in read_set

When binlog_row_image=MINIMAL, UPDATE_ROWS_EVENT may change columns
that are not in the before image. Such columns had their bit set in
table->write_set, but was missing their bit in table->read_set.

As part of this patch, bitmap_union() is extended to handle bitmaps of
different sizes, similar to bitmap_intersect().

Signed-off-by: Kristian Nielsen <knielsen@knielsen-hq.org>

Author: knielsen

mysql-test/suite/rpl/r/rpl_row_minimal_mdev31678.result

@@ -0,0 +1,17 @@
+include/master-slave.inc
+[connection master]
+connection slave;
+SET @old_format= @@GLOBAL.binlog_row_image;
+SET GLOBAL binlog_row_image=MINIMAL;
+include/stop_slave.inc
+include/start_slave.inc
+SET GLOBAL binlog_row_image= @old_format;
+connection default;
+SET SESSION binlog_row_image=MINIMAL;
+CREATE TABLE t (id INT AUTO_INCREMENT, col_int BIGINT NOT NULL, UNIQUE (col_int), KEY(id)) ENGINE=InnoDB;
+INSERT INTO t VALUES (1,1);
+UPDATE t SET id = 2;
+connection slave;
+connection master;
+DROP TABLE t;
+include/rpl_end.inc

mysql-test/suite/rpl/t/rpl_row_minimal_mdev31678.test

@@ -0,0 +1,23 @@
+--source include/have_innodb.inc
+--source include/have_binlog_format_row.inc
+--source include/master-slave.inc
+
+--connection slave
+SET @old_format= @@GLOBAL.binlog_row_image;
+SET GLOBAL binlog_row_image=MINIMAL;
+--source include/stop_slave.inc
+--source include/start_slave.inc
+SET GLOBAL binlog_row_image= @old_format;
+--connection default
+SET SESSION binlog_row_image=MINIMAL;
+
+CREATE TABLE t (id INT AUTO_INCREMENT, col_int BIGINT NOT NULL, UNIQUE (col_int), KEY(id)) ENGINE=InnoDB;
+INSERT INTO t VALUES (1,1);
+UPDATE t SET id = 2;
+ 
+--sync_slave_with_master
+ 
+# Cleanup
+--connection master
+DROP TABLE t;
+--source include/rpl_end.inc

mysys/my_bitmap.c

@@ -538,11 +538,16 @@ void bitmap_subtract(MY_BITMAP *map, const MY_BITMAP *map2)
 
 void bitmap_union(MY_BITMAP *map, const MY_BITMAP *map2)
 {
-  my_bitmap_map *to= map->bitmap, *from= map2->bitmap, *end= map->last_word_ptr;
-  DBUG_ASSERT_IDENTICAL_BITMAPS(map,map2);
+  my_bitmap_map *to= map->bitmap, *from= map2->bitmap, *end;
+  uint len= no_words_in_map(map), len2= no_words_in_map(map2);
+  uint32 num_bits= MY_MIN(map->n_bits, map2->n_bits);
+  DBUG_ASSERT_DIFFERENT_BITMAPS(map,map2);
 
-  while (to <= end)
+  end= to + MY_MIN(len, len2) - 1;
+
+  while (to < end)
     *to++ |= *from++;
+  *to|= *from & ~last_bit_mask(num_bits); /* Omit last not relevant bits */
 }
 
 

sql/log_event_server.cc

@@ -8543,9 +8543,11 @@ Update_rows_log_event::do_exec_row(rpl_group_info *rgi)
 #endif /* WSREP_PROC_INFO */
 
   thd_proc_info(thd, message);
-  // Temporary fix to find out why it fails [/Matz]
-  memcpy(m_table->read_set->bitmap, m_cols.bitmap, (m_table->read_set->n_bits + 7) / 8);
-  memcpy(m_table->write_set->bitmap, m_cols_ai.bitmap, (m_table->write_set->n_bits + 7) / 8);
+  /* Must read also after-image columns to be able to update them. */
+  bitmap_copy(m_table->read_set, &m_cols);
+  bitmap_union(m_table->read_set, &m_cols_ai);
+  /* Must update after-image columns. */
+  bitmap_copy(m_table->write_set, &m_cols_ai);
 
   m_table->mark_columns_per_binlog_row_image();