MDEV-29013 ER_KEY_NOT_FOUND/lock timeout upon online alter with long uniquebb-10.10-MDEV-29021

1. ER_KEY_NOT_FOUND
Some virtual columns were not updated because were not included in read_set
to the moment of calculation.

In Row_logs_event::do_apply_event some fields are excluded based on m_cols
value, the number of replicated rows.

We can't rely on this. Basically, we'd be satisfied, if all columns were
just set, at least for now.

2. ER_LOCK_WAIT_TIMEOUT
This is a long unique specific problem.

Sometimes, lookup_handler is created for to->file. To properly free it,
ha_reset should be called. It is usually done by calling
close_thread_table, but ALTER TABLE makes it differently. Hence, a single
ha_reset call is added to mysql_alter_table.

Also, the lifetime of lookup_handler is corrected: it's been allocated on
thd->mem_root, which in case of online alter
is event's mem_root, and can vary other ways.
It is changed to table->mem_root, which is more appropriate:
ha_reset is called only when table is closed, or in a few additional cases,
which correspond to a statement end. So memory leaks are unlikely here.

1 files changed, 7 insertions, 1 deletions

diff --git a/sql/sql_table.cc b/sql/sql_table.cc
index 29c4d09cd39..a3efcdd9785 100644
--- a/sql/sql_table.cc
+++ b/sql/sql_table.cc
@@ -11011,6 +11011,9 @@ do_continue:;
                    !(table->file->ha_table_flags() & HA_REUSES_FILE_NAMES) &&
                    !(new_table->file->ha_table_flags() &
                      HA_REUSES_FILE_NAMES));
+
+  // Close lookup_handler.
+  new_table->file->ha_reset();
   /*
     Close the intermediate table that will be the new table, but do
     not delete it! Even though MERGE tables do not have their children
@@ -11854,8 +11857,11 @@ copy_data_between_tables(THD *thd, TABLE *from, TABLE *to,
 
     // We'll be filling from->record[0] from row events
     bitmap_set_all(from->write_set);
-    // We restore bitmaps, because update event is going to mess up with them.
+    // Use all columns. UPDATE/DELETE events reset read_set and write_set to
+    // def_*_set after each row operation, so using all_set won't work.
     to->default_column_bitmaps();
+    bitmap_set_all(&to->def_read_set);
+    bitmap_set_all(&to->def_write_set);
 
     end_read_record(&info);
     init_read_record_done= false;