MDEV-8200 aria bug with insert select and lock tables

This bug happens when locking the same Aria "transactional" table
(page format) more then once with LOCK TABLES and inserting into one
of them with INSERT ... SELECT when the table is empty.

Fixed by ensuring we don't use fast bulk insert if table is opened
twice with LOCK TABLES (as this changes table->s->state)

Code changes:
- Added use_count to MARIA_USED_TABLES to be able to check if
  table is opened twice for a statement/lock table
- Don't clear history or reset info->start_state if we
  don't have versioning. One reason for the bug was
  was that info->start_state was set to point to different
  states for the two tables.  If there is no versioning
  info->start_state should always point to info->s->state.common.

Other things:
- Fixed also some typos that was noticed while scanning the code
- More DBUG_PRINT

1 files changed, 1 insertions, 0 deletions

diff --git a/storage/maria/ma_state.h b/storage/maria/ma_state.h
index 2903986e32a..d662b9899f8 100644
--- a/storage/maria/ma_state.h
+++ b/storage/maria/ma_state.h
@@ -34,6 +34,7 @@ typedef struct st_used_tables {
   struct st_maria_share *share;
   MARIA_STATUS_INFO state_current;
   MARIA_STATUS_INFO state_start;
+  uint use_count;
 } MARIA_USED_TABLES;