MDEV 15532 Assertion `!log->same_pk' failed in row_log_table_apply_delete

The reason for the failure is that
thd->mdl_context.release_transactional_locks()
was called after commit & rollback even in cases where the current
transaction is still active.

For 10.2, 10.3 and 10.4 the fix is simple:
- Replace all calls to thd->mdl_context.release_transactional_locks() with
  thd->release_transactional_locks(). The thd function will only call
  the mdl_context function if there are no active transactional locks.
  In 10.6 we will better fix where we will change the return value for
  some trans_xxx() functions to indicate if transaction did close the
  transaction or not. This will avoid the need of the indirect call.

Other things:
- trans_xa_commit() and trans_xa_rollback() will automatically
  call release_transactional_locks() if the transaction is closed.
- We can't do that for the other functions as the caller of many of these
  are doing additional work (like close_thread_tables) before calling
  release_transactional_locks().
- Added missing abort_result_set() and missing DBUG_RETURN in
  select_create::send_eof()
- Fixed wrong indentation in injector::transaction::commit()

1 files changed, 3 insertions, 0 deletions

diff --git a/sql/mdl.cc b/sql/mdl.cc
index 9eeb82eeffd..f2b205a86f2 100644
--- a/sql/mdl.cc
+++ b/sql/mdl.cc
@@ -2842,6 +2842,9 @@ void MDL_context::rollback_to_savepoint(const MDL_savepoint &mdl_savepoint)
 void MDL_context::release_transactional_locks()
 {
   DBUG_ENTER("MDL_context::release_transactional_locks");
+  /* Fail if there are active transactions */
+  DBUG_ASSERT(!(current_thd->server_status &
+                (SERVER_STATUS_IN_TRANS | SERVER_STATUS_IN_TRANS_READONLY)));
   release_locks_stored_before(MDL_STATEMENT, NULL);
   release_locks_stored_before(MDL_TRANSACTION, NULL);
   DBUG_VOID_RETURN;