MDEV-39081 InnoDB: tried to purge non-delete-marked record, assertion fails in row_purge_del_mark_error

Reason:
=======
Following the changes in MDEV-38734, the server no longer marks
all indexed virtual columns during an UPDATE operation.
Consequently, ha_innobase::update() populates the upd_t vector
with old_vrow but omits the actual data for these virtual columns.

Despite this omission, trx_undo_page_report_modify() continues to
write metadata for indexed virtual columns into the undo log. Because
the actual values are missing from the update vector, the undo log
entry is recorded without the historical data for these columns.

When the purge thread processes the undo log to reconstruct a
previous record state for MVCC, it identifies an indexed virtual
column but finds no associated data.

The purge thread incorrectly interprets this missing data as a NULL
value, rather than a "missing/unrecorded" value. The historical
record is reconstructed with an incorrect NULL for the virtual column.
This causes the purge thread to incorrectly identify and purge
records that are not actually delete-marked, leading to abort
of server.

Solution:
=========
ha_innobase::column_bitmaps_signal(): Revert the column-marking
logic to the state prior to commit a4e4a56, ensuring all
indexed virtual columns are unconditionally marked during an UPDATE.

The previous "optimization" attempted to manually detect indexed
column changes before marking virtual columns. The manual check
for indexed column modifications is redundant. InnoDB already
provides the UPD_NODE_NO_ORD_CHANGE flag within row_upd_step().
This flag is being used in trx_undo_page_report_modify() and
trx_undo_read_undo_rec() should log or read virtual column values.

Refactored column_bitmaps_signal() to accept a mark_for_update
parameter that controls when indexed virtual columns are marked.
TABLE::mark_columns_needed_for_update() is the only place that needs
mark_for_update=true because only UPDATE operations need to mark
indexed virtual columns for InnoDB's undo logging mechanism.

INSERT operation is already handled by
TABLE::mark_virtual_columns_for_write(insert_fl=true).
Even the commit a4e4a56 changes are
going to affect TABLE::mark_virtual_column_for_write(false) and
It is called during UPDATE operation, and that's when
column_bitmaps_signal() needs to mark  indexed virtual columns.

Online DDL has separate code path which is handled by
row_log_mark_virtual_cols() for all DML operations

Author: Thirunarayanan

mysql-test/suite/vcol/r/vcol_keys_innodb.result

@@ -303,3 +303,23 @@ IF(@@innodb_sort_buffer_size < count(*)*200, 'GOOD', 'WRONG SIZE')
 GOOD
 alter table t1 drop column va;
 drop table t1;
+#
+#  MDEV-39081 InnoDB: tried to purge non-delete-marked record,
+#   assertion fails in row_purge_del_mark_error
+#
+CREATE TABLE t1(
+pk INT AUTO_INCREMENT,
+f1 INT DEFAULT 0,
+f2 INT as (1 + 1) VIRTUAL,
+KEY (f1), PRIMARY KEY (pk), UNIQUE (f2)) ENGINE=InnoDB;
+START TRANSACTION WITH CONSISTENT SNAPSHOT;
+CONNECT con1,localhost,root,,;
+INSERT INTO t1 (pk) VALUES(1);
+DELETE FROM t1;
+INSERT INTO t1 (pk) VALUES(1);
+UPDATE t1 set f1 = 2;
+disconnect con1;
+connection default;
+COMMIT;
+InnoDB		0 transactions not purged
+DROP TABLE t1;

mysql-test/suite/vcol/t/vcol_keys_innodb.test

@@ -135,3 +135,25 @@ insert t1 (id,a,c) select seq,seq,seq from seq_1_to_330;
 select IF(@@innodb_sort_buffer_size < count(*)*200, 'GOOD', 'WRONG SIZE') from t1;
 alter table t1 drop column va;
 drop table t1;
+
+--echo #
+--echo #  MDEV-39081 InnoDB: tried to purge non-delete-marked record,
+--echo #   assertion fails in row_purge_del_mark_error
+--echo #
+CREATE TABLE t1(
+  pk INT AUTO_INCREMENT,
+  f1 INT DEFAULT 0,
+  f2 INT as (1 + 1) VIRTUAL,
+  KEY (f1), PRIMARY KEY (pk), UNIQUE (f2)) ENGINE=InnoDB;
+START TRANSACTION WITH CONSISTENT SNAPSHOT;
+
+CONNECT(con1,localhost,root,,);
+INSERT INTO t1 (pk) VALUES(1);
+DELETE FROM t1;
+INSERT INTO t1 (pk) VALUES(1);
+UPDATE t1 set f1 = 2;
+DISCONNECT con1;
+CONNECTION default;
+COMMIT;
+--source ../innodb/include/wait_all_purged.inc
+DROP TABLE t1;

sql/filesort.cc

@@ -962,7 +962,7 @@ static ha_rows find_all_keys(THD *thd, Sort_param *param, SQL_SELECT *select,
                select->cond : select->pre_idx_push_select_cond));
   if (sort_cond)
     sort_cond->walk(&Item::register_field_in_read_map, 1, sort_form);
-  sort_form->file->column_bitmaps_signal();
+  sort_form->file->column_bitmaps_signal(false);
 
   if (quick_select)
   {

sql/ha_partition.h

@@ -577,13 +577,13 @@ class ha_partition final :public handler
     m_file[part_id]->update_create_info(create_info);
   }
 
-  void column_bitmaps_signal() override
+  void column_bitmaps_signal(bool mark_for_update) override
   {
     for (uint i= bitmap_get_first_set(&m_opened_partitions);
         i < m_tot_parts;
         i= bitmap_get_next_set(&m_opened_partitions, i))
     {
-      m_file[i]->column_bitmaps_signal();
+      m_file[i]->column_bitmaps_signal(mark_for_update);
     }
   }
 

sql/ha_sequence.h

@@ -157,8 +157,8 @@ class ha_sequence :public handler
   { return file->check_and_repair(thd); }
   bool is_crashed() const override
   { return file->is_crashed(); }
-  void column_bitmaps_signal() override
-  { return file->column_bitmaps_signal(); }
+  void column_bitmaps_signal(bool mark_for_update) override
+  { return file->column_bitmaps_signal(mark_for_update); }
 
   /* New methods */
   void register_original_handler(handler *file_arg)

sql/handler.cc

@@ -4482,6 +4482,8 @@ int handler::update_auto_increment()
 /** @brief
   MySQL signal that it changed the column bitmap
 
+  @param mark_for_update  whether to mark indexed virtual columns
+			  for UPDATE operations
   USAGE
     This is for handlers that needs to setup their own column bitmaps.
     Normally the handler should set up their own column bitmaps in
@@ -4492,7 +4494,7 @@ int handler::update_auto_increment()
     rnd_init() call is made as after this, MySQL will not use the bitmap
     for any program logic checking.
 */
-void handler::column_bitmaps_signal()
+void handler::column_bitmaps_signal(bool mark_for_update)
 {
   DBUG_ENTER("column_bitmaps_signal");
   if (table)

sql/handler.h

@@ -4054,8 +4054,11 @@ class handler :public Sql_alloc
     call. Normally the handler should ignore all calls until we have done
     a ha_rnd_init() or ha_index_init(), write_row(), update_row or delete_row()
     as there may be several calls to this routine.
+
+    @param mark_for_update  whether to mark indexed virtual columns
+                            for UPDATE operations
   */
-  virtual void column_bitmaps_signal();
+  virtual void column_bitmaps_signal(bool mark_for_update);
   /*
     We have to check for inited as some engines, like innodb, sets
     active_index during table scan.

sql/sql_admin.cc

@@ -1042,7 +1042,7 @@ static bool mysql_admin_table(THD* thd, TABLE_LIST* tables,
                                   ER_THD(thd, ER_NO_EIS_FOR_FIELD),
                                   column_name->str);
           }
-          tab->file->column_bitmaps_signal();
+          tab->file->column_bitmaps_signal(false);
         }
         if (!lex->index_list)
           tab->keys_in_use_for_query.init(tab->s->keys);

sql/sql_sequence.cc

@@ -695,14 +695,14 @@ int sequence_definition::write(TABLE *table, bool all_fields)
   save_write_set= table->write_set;
   save_read_set=  table->read_set;
   table->read_set= table->write_set= &table->s->all_set;
-  table->file->column_bitmaps_signal();
+  table->file->column_bitmaps_signal(false);
   store_fields(table);
   if (unlikely((error= table->file->ha_write_row(table->record[0]))))
     table->file->print_error(error, MYF(0));
   table->rpl_write_set= save_rpl_write_set;
   table->read_set=  save_read_set;
   table->write_set= save_write_set;
-  table->file->column_bitmaps_signal();
+  table->file->column_bitmaps_signal(false);
   return error;
 }
 

sql/sql_table.cc

@@ -12621,7 +12621,7 @@ copy_data_between_tables(THD *thd, TABLE *from, TABLE *to,
   if (from_row_end)
     bitmap_set_bit(from->read_set, from_row_end->field_index);
 
-  from->file->column_bitmaps_signal();
+  from->file->column_bitmaps_signal(false);
 
   to->file->prepare_for_insert(0);
   DBUG_ASSERT(to->file->inited == handler::NONE);